Star Tracks - Thursday, September 20, 2007

School's back in session! Super cheerleader Hayden Panettiere shakes up her routine while filming Heroes Wednesday in Los Angeles. Season two of the popular NBC show premieres on Sept. 24.

Diddy gives photographers a whiff of his new fragrance, Unforgivable Woman, at a launch party Wednesday in New York. "It follows in the footsteps of Unforgivable Man," he told PEOPLE. "It was understated, but yet it had a seductive scent to it."

No, she's not really sleeping off a hangover! Jessica Simpson gets a wake-up call as she continues shooting Major Movie Star Wednesday in Hollywood. But the singer-actress is already thinking about her next musical move – a possible country album.

It's a wardrobe match for Jessica Alba and her Good Luck Chuck costar Dane Cook (not pictured), who both sported Prada for the premiere of their comedy in Westwood, Calif., on Wednesday. Of coordinating their wardrobe, Alba joked with reporters: "Great minds thing alike."

Beyoncé arrives at Diddy's fragrance launch party with boyfriend Jay-Z (not pictured) – and a darker do that had guests buzzing. "I didn't recognize her," Diddy told PEOPLE. Tell us if you like her new hair color.

After presenting at Sunday's Emmys with her Entourage, Eva Longoria and her one-and-only – husband Tony Parker – make a beverage stop in Hollywood on Wednesday.

Can you smell what The Rock is cookin'? Dwayne Johnson plays master stylist on Barbie during a segment for MTV's TRL on Wednesday. The actor was promoting The Game Plan, a comedy in which he plays a football player whose life changes after his glitter-obsessed 7-year-old daughter moves in.

After nearly taking a tumble, a colorfully outfitted Paris Hilton earns her zigzags – and stripes! – while out shopping Wednesday at Fred Segal in West Hollywood.

Carrie and Big are back! Sarah Jessica Parker and Chris Noth cross paths once again on the set of their much-anticipated Sex and the City: The Movie, filming Wednesday in New York City.

He must like what he sees! Prince gives his female companion some skin while taking in the Matthew Williamson Spring/Summer 2008 fashion show in London on Wednesday.

Celebrating the debut of their new show, (from left) Nicole Fiscella, Jessica Szohr, Blake Lively and Nan Zhang put aside any cattiness for a group snapshot at the Gossip Girl premiere party at New York City hot spot Tenjune on Tuesday.

A relaxed Jennifer Aniston moves along with filming He's Just Not That Into You on Thursday in Hollywood. The actress was reportedly joined on set by her costar Ben Affleck (not pictured).

In town shooting a film, a scruffy George Clooney makes an A-list exit Thursday from New York's Chelsea neighborhood.

It's a snap for Kim Kardashian, who puts her new swag – a Casio digital camera – to use on her way in to the Maxim Style Awards bash Wednesday at Hollywood club Avalon. Inside, the socialite mingled with guests including Heroes star Masi Oka and Gabrielle Union.

After receiving a standing ovation at an awards show earlier this month, Amy Winehouse stages another soulful performance Wednesday at the Music of Black Origin Awards in London.