Ever wonder how much shoe game young Hollywood has? PEOPLE checked in with Hayden Panettiere and Michelle Trachtenberg at the unveiling of Stuart Weitzman’s Young Hollywood Cares collection during Fashion’s Night Out to get the scoop on staying well-heeled.

“It’s like wearing stilts, but they look good,” chuckled Hayden Panetierre about the stacked platform booties she co-designed with Stuart Weitzman. “That’s the great thing about the wedge in the front. It gives that illusion that your foot is tilted much more than it is.” And unlike some celebrity collaborations, creating the $498 “Hayden” was a labor filled with love. The star, who said her involvement was “just shy of stitching,” came to New York solely to support the collection, the proceeds of which benefit Dr. Marsha Moses’ pioneering research in ovarian cancer.

Trachtenberg spouts an equally straightforward style philosophy. Rocking a gunmetal gray shift and her “Michelle” pumps — a deep purple calfskin platform — the Gossip Girl star confided, “I don’t really follow trends. If you walk out of the fitting room like, ‘I don’t know,’ and a salesperson has to convince you to buy it, you’re never going to wear it and it’s going to sit in your closet.”

And all of this designing business has at least one up-and-comer thinking bigger picture: “My friend and I make necklaces,” Panetierre couldn’t help but reveal of her “underground” jewelry collection, Chain Gang. “They are beads, almost looks like a rosary, except it’s got all these different charms on it and we make them by hand.”

–Justine Harman

MEET MORE STAR DESIGNERS!

For her role in the upcoming Gimme Shelter, Vanessa Hudgens didn’t just play her character — she became her character. “The tattoo, the hair, the clothes, the piercings, the attitude, the everything,” she tells PEOPLE. “The walk, the talk … it was a completely new person. I really did look like a boy.” Gaining 10 lbs. for the role, plus chopping her hair and adding several piercings “automatically puts you into a different headspace,” she says. “Not to mention the places we were filming. We were in the grimiest, dirtiest places, and I was fighting every day, being fought, being beat down and it was all extremely draining even though it was acting.” Speaking to PEOPLE Monday at Neutrogena’s Wave for Change event in Los Angeles, the actress, still sporting cropped hair, said life has calmed since filming — and aside from a summer of skydiving and tattooing, she’s happy to be helping a good cause. “I love working with charities, I love children, and there is so much we can do,” she said. “Wave for Change makes it super easy for kids to make a difference and give back.” Hudgens, Hayden Panettiere and Miranda Cosgrove each designed a tote bag for Wave for Change, available through Aug. 31 for those who purchase two Neutrogena products at Target. For each product purchased, Neutrogena will donate one dollar to globalgiving.org — up to $250,000. Hudgens explained that her tote was made to help disaster relief victims. “It’s ‘Hope,’ because everybody needs hope in times of need,” she said. “Some of the inspiration came from the movie … my character names her baby Hope.” Panettiere, also a face of Neutrogena, told PEOPLE that hers was designed with animal charities in mind. “It’s in the shape of a heart, but it’s made up of dolphins and whales and birds and stingrays and swordfish,” she explained. “It was definitely a collaboration.” –Reporting by Reagan Alexander

SEE MORE ON-SET STYLE IN ‘LIGHTS! CAMERA! FASHION!’

Trendy stars like Vanessa Hudgens, Hayden Panettiere and Miranda Cosgrove are taking a fashionable approach to charity! To celebrate the second year of Neutrogena’s Wave for Change campaign — a charitable intiative that makes it easy for teens to give back and support those in need — the leading ladies (and Neutrogena brand ambassadors) have each designed a signature tote bag with a different cause in mind. “My tote bag [right] is benefiting disaster relief projects here in the United States,” Hudgens tells PEOPLE. “It’s cool that you can help others and get a fun, fashionable bag. It was fun to design and it’s the perfect tote for summer to use when shopping or even by the pool or at the beach.” Panettiere designed her tote [left] for environmental charities and Miranda Cosgrove made hers [center] to benefit educational causes. Other stars are getting involved, too — by supporting their famous friends! “Hayden … did a beautiful job,” pal and fellow Neutrogena ambassador Emma Roberts said. “I think I am going to use hers so I can show support for the campaign and also have a great summer tote.” The stars’ Wave for Change bags are available July 1 through Aug. 31 for those who purchase two Neutrogena products at Target. And for every Neutrogena acne, cleansing or cosmetics product sold, the company will donate $1 to GlobalGiving.org — up to $250,000! Visit neutrogena.com/waveforchange for details. Tell us: Which Neutrogena Wave for Change tote is your favorite? –Kim Peiffer

YOU ASKED, WE FOUND: STAR LOOKS

Forget shortcuts: this summer, stars are going long. Hayden Panettiere and Jessica Alba are the latest celebs to take their hair to new lengths with extensions. Panettiere debuted her updated look at the Vans Custom Culture Event in New York City on June 2. The actress, who chopped her locks in April of 2010 because she “likes abrupt changes,” added wavy blonde strands to her head, returning to her Heroes roots. Alba, expecting her second child with husband Cash Warren, turned up at the Covenant House California Gala in Los Angeles on Thursday with brunette tresses that flowed well past her shoulders — a major contrast to the shorter style she sported as recently as late May. The ladies join Christina Ricci as the latest to lengthen their locks for the warm-weather months. Tell us: Would you rather go long or short for summer?

VOTE ON STAR HAIR CHANGES IN ‘WHAT’S HER BEST HAIR?’

There are two new names on the tips of Tinseltown tongues: those of Australian design team camilla and marc! Just last month, the brother-sister duo captured the hearts of fashionistas including Ashley Tisdale, Rachel Bilson and Hayden Panettiere, and the stars definitely did the designers proud. “She keeps the look well balanced and effortlessly chic,” Camilla Freeman-Topper tells PEOPLE of Tisdale, who paired her $460 “Blind Call” dress with a LOFT necklace. As for Bilson, “Rachel’s got something going on … her style is individual and unique. I love seeing girls take one of our pieces and make it their own,” Freeman-Topper gushes of the $690 “Equinox” frock she wore out in N.Y.C. And though Panettierre selected an overtly-feminine look, the designer thinks she perfectly accessorized the $1,010 “Cantel” mini. “Coupled with the hair, makeup and delicate shoes, Hayden made the look stylish and sophisticated,” she praises. We know Hollywood is hot for the brand, but want to know what you think. –Justine Harman

WEIGH IN ON MORE CELEB STYLE IN ‘LAST NIGHT’S LOOK: HIT OR MISS?’

Pint-sized Scream 4 star Hayden Panettiere seems to be a designer’s dream. The actress can work any look — long, short, couture, casual — and is a style chameleon, coolly changing hairstyles and makeup in the blink of an eye. So can an actress who’s sported so many looks and hit as many red carpets pinpoint her three favorite dresses ever? The answer is yes. In a recent chat with PEOPLE, Panettiere says this chocolate halter, which she wore to the Elton John AIDS Foundation Oscar Party in March of 2010, is one of her best. “This Amanda Wakeley dress is so ethereal and feminine and easy to wear,” she says. “I love the Grecian style.” Another obsession? The turquoise and black lace number she sported at the 2010 CMT Awards. “I’m really into jewel tone dresses. This Pucci dress is a fun way to wear bright color, and its tight fit made it modern.” Panettiere rounds out her top three with a white stunner she wore to Elton John’s 2011 post-Oscar bash. “I love this Luca Luca dress,” she says, “because it was inspired by old Hollywood with a contemporary twist, which makes it youthful and elegant.” Tell us: Which of Panettiere’s red carpet looks do you prefer? –Reporting by Justine Harman

Albert Michael/Startraks

When Vanessa Hudgens and Hayden Panettiere hit the beach yesterday in L.A., it wasn’t just to soak up the rays. The two beautiful actresses (and Neutrogena brand ambassadors ) joined forces to announce the new Neutrogena Wave for Change campaign, a charitable initiative that lets teens help the company decide how to distribute up to $200,000 from sales of the Wave Sonic Power-Cleaner and Oil-Free Acne Wash Pink Grapefruit product sold for disaster relief, education and environmental causes through GlobalGiving. Through August 23, visitors to the Neutrogena Facebook page can take a quiz to see which cause they’d like to support, which will help determine where funding eventually goes. “Often people want to participate, but they don’t know how so the fact Neutrogena is opening the door and kids are getting to be a part of something and help the world is an amazing thing to be a part of,” says Panettiere. Hudgens seconds the feeling, telling PEOPLE that “It’s so cool that Neutrogena is letting the fans go to Neutrogena’s Facebook page to take a quiz to determine how the money raised for charity is being distributed. By taking a few minutes to join in, everyone can make a big difference in the world.” Go to Facebook.com/Neutrogena to take the quiz today!

Frederick Breedon/WireImage

When it comes to her hair, Hayden Panettiere is proving herself quite the drama queen. After dying her tresses auburn and then chopping her shoulder-grazing locks into a pixie cut earlier this year, the Heroes star rocked an even shorter, back-to-blonde style at Wednesday’s 2010 CMT Music Awards. “It wasn’t scary,” the 20-year-old actress explained to PEOPLE of taking the plunge. “I’m pretty spontaneous. I like abrupt changes–it excites me.” Dressed in an asymmetrical turquoise-and-black Pucci dress, the petite vixen cut a striking figure — anchored, of course, by the bold new cut. “I love it — it’s daring and it’s easier for me,” she said. “You always try to find your own sense of style, so when I chopped my hair off I felt like I was my own self in my own way. I didn’t feel like I was trying to emulate anyone. I felt very me.” Tell us: What do you think of Hayden’s cut? –Marissa Patlingrao Cooley; reporting by Eileen Finan

CHECK OUT ALL THE STYLISH STARS AT THE CMT MUSIC AWARDS.

SDB/StarTraks; AW/Getty; Landov; SG/Getty

The pixie cut seems to be the hairstyle du jour these days, as evidenced by the recently cropped heads of Hollywood fashion plates like Jessica Stroup, Hayden Panettiere, Renée Zellweger and most recently Michelle Williams. With so many cool ways to rock this neck-baring look–from Jessica’s dark cropped mop and Hayden’s slicked-back style to Renée’s straight, honey-toned tresses and Michelle’s tousled platinum side-sweep–it’s tough to decide which of these beauties is pulling it off most glamorously. Tell us: Who rocks her pixie cut best? Vote! –Marissa Patlingrao Cooley

Angela Weiss/Getty

It must be spring fever! Following the lead of stars like Heidi Klum and Kate Beckinsale, Hayden Panettiere is the next Hollywood vixen to welcome the warmer weather with a shorter do. The star debuted a dramatically cropped cut at an Earth Day celebration yesterday in Los Angeles. And while the petite beauty, is no stranger to changing up her color, this sophisticated new hairstyle is a dramatic departure from the longer tresses she’s known for. Tell us: Do you like Hayden Panettiere’s new short cut or do you prefer her with longer hair? –David Yi

Evan Agostini/AP

As one of Hollywood’s more recognizable blondes, Heroes star Hayden Panettiere gave new meaning to “red carpet reveal” when she turned up at the Temple Grandin premiere in New York this week with newly auburn hair. As much as we love the new look, such a drastic color change is always a bold move–especially in Hollywood. So our big question for her was, why red now? “Because I could, because I was done with the season,” she explained to PEOPLE. “I was like, ‘I need to change, I need to get myself out of this slot. I don’t feel like a blonde right now!’” In true superstar fashion, the actress didn’t stop with her hair, and had her stylist touch up her brows as well. “I hope they match,” she said, continuing, “Eyebrows very much frame the face.” Despite the color change, Hayden tells us that she isn’t through with the change-ups. “I was going to go dark,” she said of her original hair color plan. “And then I decided to go red first — and then dark.” We can’t wait to see what’s next! Tell us: Do you like Hayden’s new color, or do you prefer her as a blonde?–Katherine Kluznik Rentmeester, reporting by Jeffrey Slonim

Vince Flores/Celebrity Photo

One of the benefits of being a Hollywood starlet is getting your hands on designer duds before they hit store racks. And the much-anticipated Jimmy Choo for H&M line is no exception. Clad in sparkling black and leather looks from the yet-to-be-seen collection, stars like Hayden Panettiere, Kate Walsh, Paris and Nicky Hilton, Whitney Port, Rashida Jones, Olivia Wilde, Diablo Cody and more celebrated the impending launch of the designer collaboration. “I wanted to create looks that women could go out to holiday parties, and events in,” Tamara Mellon, Jimmy Choo founder and president, tells PEOPLE at the party, which featured a performance by rapper M.I.A. “My aesthetic is to always have a rock and roll edge.” Though this line will come with a much lower price tag than the high fashion heels the brand is known for, Diablo Cody tells PEOPLE that the name still makes her think luxe. “I think about stilettos, I think about beautiful fabrics, and I think about money that I shouldn’t have spent,” says the Oscar-winning screenplay writer for Juno. From studded sandals and hot pink clutches to velvet tuxedo jackets and high-waisted leather leggings, it looks like Hollywood’s leading ladies are loving Jimmy Choo for H&M just as much as the luxury shoe line–and so are we! Jimmy Choo for H&M will hit stores on Nov. 14, but in the meantime, you can check out some of the styles on Hayden, Kate, Whitney and more in today’s Hit or Miss.–Reporting by Reagan Alexander

Jen Lowery/Startraks

Doing good sure did look appealing this weekend at the Neutrogena Fresh Faces of Music event to benefit VH1′s Save the Music Foundation. Two of Neutrogena’s superstar spokespeople, Hayden Panettiere and Vanessa Hudgens, turned out to show their support for keeping music in schools. And the duo did a lot more than just show off their flawless skin — they lent a hand by presenting a $30,000 check to a South Los Angeles middle school to jump-start their music program. “It’s such an important thing, music and creativity,” Hayden tells PEOPLE. “I’ve heard vineyards will play Mozart while the grapes are growing and it really does make a massive, massive difference.” But no beauty-supported event is complete without a little shop talk, and Hudgens was quick to share her favorite beauty must-have. “Things are always on the go for me so I love The Wave,” Vanessa tells PEOPLE of Neutrogena’s deep-cleansing power gadget. “I just throw it in my purse and go on my merry way.” Tell us: What’s your go-to budget beauty tool? — reporting by Nina Tyler

Dooney & Bourke

The Heroes star isn’t just saving the world from evil on TV — she’s helping to bring good design to your closet, too. Hayden Panettiere, who is Dooney & Bourke’s spokesmodel, has teamed up with the label’s designer Peter Dooney to create the perfect bag for Spring 09. Named after the star herself, the “Hayden Clutch” is made from Italian calfskin and fastened with a 24 carat gold plated lion head, inspired by her astrological sign the Leo. PEOPLE caught up the new handbag designer who told us she was part of the design process from the initial drawing to the lion’s head clasp. “Instead of putting my name on it, I put a lions head on it. It’s a way of representing me,” says Hayden. The clutch shape was also her idea. “I asked if I could design a clutch because it’s something that I’ve familiar with because I carry them around all of the time.” The bag will come in a variety of colors including blue, red, black, white, brown, hot pink (Hayden’s favorite) and purple. The Hayden Clutch, $295, will hit Dooney & Bourke stores nationwide in December. The Hayden Clutch isn’t the first bag by the young star. Hayden also lent her skill to the Hayden Bag, a large patent number, for the Fall 08 collection. Though her bags are a big hit, the star doesn’t have any desire to become a fashion designer. “I’m going to stick to acting. If I designed anything it would probably be something for myself, more of a personal thing. I’m not interested in becoming a designer.”Tell us: What do you think of the Hayden clutch? Will you buy one?

Jason Merritt/FilmMagic; Frazer Harrison/Getty; UPI /Landov

Looking at the Emmy Awards red carpet tonight, one might think that it was mid-summer with all the bright colors ruling the red carpet. Canary yellow took center stage with Saffron Burrow’s Herve Leroux gown, Mariska Hargitay‘s Carolina Herrera and Teri Hatcher‘s Monique Lhuillier. Shades of aqua and turquoise made a great showing, too, from Christina Applegate to Cynthia Nixon to Mary Louise Parker. And, of course, there were plenty of black and navy gowns on Hayden Panettiere, Debra Messing and America Ferrera. Eva Longoria and fellow Desperate Housewives Dana Delany and Felicity Huffman made a dazzling case for silver accents. And for beauty, retro waves ruled from Kyra Sedgwick to Sandra Oh, and bold red lips turned up on Kate Walsh and more. Click here to see all of the fashion and beauty coverage from the Emmy Awards.

She’s one of Hollywood’s hottest superheroes, and now Hayden Panettiere is setting her sights on singing — and she’s letting Candie’s in on the action. The footwear giant has just announced that as part of the Heroes actress’s second season as a spokesmodel for their juniors line, they will feature Hayden’s first-ever music video, “Wake Up Call,” as a television commercial spot. And although the single from her debut album won’t be available to download from iTunes until August 5, she’s giving PEOPLE a first look and listen. Find yourself craving the styles she shows off in the video and print ads? You’re in luck. The items will be available as part of Candie’s back-to-school collection exclusively for Kohl’s. You’ve seen, you’ve heard. Tell us: What do you think of Hayden’s single?

See Hayden’s print ad by clicking through!

Courtesy Candie’s

Andy Fossum/Startraks

Hayden Panettiere may keep mum on certain things — like her relationship with costar Milo Ventimiglia — but she was happy to chat with PEOPLE at the Ford Flex Rally in L.A. this weekend about her sassy new bob. The eighteen-year old actress tells PEOPLE, “With extensions and stuff because my hair is down to here still on the show, it’s like every other day it’s a bob. And then it’s dark, and then it’s blonde and long, so it’s kind of nice not to have to wake up in the morning and have your hair sticking out to one side.” And the besides being able to change up her style, what’s the best part of her short new do? “It’s like, oh my gosh, it’s so easy! I can run out the door.” As for the dark hair that Hayden’s been sporting on set, she confides that “I play two different Claires,” one of which will be evil. Tell us: What do you think of Hayden’s new bob?

Barnsley/Symons/Pacific Coast News

Heroes star Hayden Panettiere may be a self-proclaimed bikini girl, but we can’t always say the same when it comes to the daunting task of finding a flattering yet stylish swimsuit. One of our biggest gripes is tracking down a chic bikini whose top and bottom are sold as a set, making comfort difficult for those of us who aren’t perfectly proportioned. That’s why we love swimwear lines from Shoshanna and Elizabeth Hurley, who sell their tops and bottoms separately. With swimsuit season coming upon us, the editors at StyleWatch wanted to hear your thoughts on finding the perfect bikini. Tell us: What’s your biggest anxiety when it comes to buying a swimsuit?

Bauer-Griffin

We’ve already confessed that Rihanna is our latest fashion crush. And yet again, the singer struck a fashion high note — leaving her New York hotel toting this Kooba bag that accessorized her biker-chic look. Her Heather shoulder bag, trimmed with vivid day-glo piping, has a retro ’80s vibe that we love. You can order the same one, $465, at kooba.com, or nab a smaller version, the Bennie clutch, for a more affordable $295. And you’ll definitely be in good company — Jessica Biel, Jessica Alba and Hayden Panettiere have also been spotted carrying Kooba handbags.

Shirley Buhl/Pacific Coast News

The whales are not the only thing the Heroes star is trying to save. Hayden Panettiere also wants to save the planet. While tugging designer bags, like her Kooba Elisha tote, the budding humanitarian opts for eco-friendly clothing lines like her Gypsy 05′ hoodie. The Gypsy 05′ organic “French Rose” hoodie is made using fabric derived from bamboo, low impact dyes and a 90% organic printing process. We sense the young starlet is paving her way into Hollywood’s activist hall of fame–keep it up! We found Hayden’s eco-friendly looks– and her fab bag!

Get Hayden’s Eco-Friendly Hoodie:
Gypsy O5′ French Rose Hoodie, $130, singer22.com

Love Hayden’s bag? Get the Kooba Elisha Shoulder Tote, $575, at neimanmarcus.com and for a similar bow-ed bag, try this large shopper, $95, from ninewest.com