In the tradition of P. Diddy, J. Lo, and Gwen Stefani, Justin Timberlake has added designer to his ever-expanding resume. On Tuesday night, with his best friend and business partner Trace Ayala, he unveiled the Spring/Summer 2007 "Street Sexy" collection for William Rast, the men's and women's casual-wear label named for Timberlake's and Ayala's grandfathers, respectively. Held at Social Hollywood, their runway show had Cameron Diaz, Nicky and Paris Hilton, Patrick Dempsey, Wilmer Valderrama, and superstylist Rachel Zoe sitting front-row. The rockabilly collection, which was inspired by the duo's Tennessee roots, included plenty of denim, vests, and short shorts, plus a few girly pleated dresses. "I enjoyed it because I'm a clotheshorse," said Eve, who has her own clothing line, Fetish, which she's currently revamping. "Justin has great style, so I'm not surprised."

Eddie Murphy, Bill Maher, and Timberlake's ex-bandmate J.C. Chasez skipped the show in favor of the after-party, held a few doors down at Boulevard3. A jam session that included Timberlake, Will.i.am of Black Eyed Peas, Adam Levine from Maroon 5, and Timbaland was the highlight of the evening, but Diaz's mind was still on the clothes. "The great thing about these jeans is that they fit every body type," said the new brunette, who was clad in her boyfriend's denim. "This is something that comes so natural for them, and clothing has always been a connection for both Trace and Justin, so I'm really proud."

— Victoria Namkung