HOLLYWOOD -- Justin Timberlake has been dishing out new FutureSex/LoveSounds tunes in recent months, but on Tuesday he found time to unveil some fresh threads too. JT introduced his William Rast clothing line before a jam-packed, celebrity-studded audience at hotspot Social Hollywood -- the runway show was his first as a fashion designer.

"The most we can ask for is that there be no hitches, and there were no hitches," Timberlake said backstage after the show. "I've always been interested in fashion, but I've always been on the other side of it: I always received free clothing from amazing designers."

Now it's Timberlake who's doing the designing, alongside best friend and business partner Trace Ayala (see [article id="1512811"]"Timberlake Delivers 'Little Baby,' Writes New Tracks With Fellow Ex-Mouseketeer"[/article]).

"It's something I've always wanted to do, and I think it was just perfect timing for the both of us and a perfect combination, really," Ayala said.

"He talked me into it," Timberlake interrupted.

The evening's runway show previewed the line's 2007 spring/summer collection. That includes gingham bustier tops and muted minidresses for women, dress shirts and sweater vests with skinny ties for men -- and a heavy emphasis on denim for everyone.

"What we've been really successful with has been the denim, and in our generation, denim is a staple," Timberlake explained, sounding like a seasoned fashion vet. "It's something you build an outfit around, so that's kind of where we always start from. And one thing that we were apprehensive to go with was pinstripe denim. But it seems everyone we show it to loves it."

That seemed to be the case at Social Hollywood, where girlfriend Cameron Diaz and other fashion-savvy celebs including Paris and Nicky Hilton and Eve were treated to a very untraditional runway show. The event came across as more a stylish mash-up of burlesque and breakdancing inspired by the classic '80s film "The Outsiders" than a standard fashion show, but the crowd appeared to be won over all the same.

"He's been working so hard on it," gushed a brunette-haired Diaz, who sat admiringly at the runway's 50-yard line. "Anything he does, he gives all of himself to. He has great style and he loves fashion."

"Obviously he knows what he's doing," former 'NSYNC bandmate JC Chasez said. "He's got a great eye, man. He's set a trend for the last two years with his looks, T-shirt and hoodies with suit jackets."

"Artists make some of the best designers to me because they know how to keep it hot and sexy and moving forward," "American Idol" judge Randy Jackson said. "Creative people do it the best."

For the show's afterparty at Boulevard3, Timberlake hit the stage with some special guests and gave the crowd gathered at the newly minted club a small taste of the FutureSex/LoveShow tour he announced the same day (see [article id="1543352"]"Justin Timberlake Announces North American Arena Tour Dates"[/article]).

Tight choreographed dance moves gave way to acoustic guitar as Timberlake played and performed "Like I Love You." Adam Levine joined JT onstage, harmonizing through a crowd-pleasing rendition of Maroon 5's "This Love," and then, with Timbaland in tow, Timberlake brought the house down with "SexyBack."

For more sights and stories from concerts around the country, check out MTV News Tour Reports.