Parties! The style, stars and scoop from Hollywood's hottest events

Before the revelry at the after-party got underway, 21 stars Jim Sturgess and Kate Bosworth (in Calvin Klein) welcomed guests to a screening of the flick at the IFC Center in New York City's West Village. "The studio told us just to go and hang out in Vegas and gamble," Bosworth admitted when asked how she prepared for her role as a brainy bombshell in the movie, which hits theaters on March 28th.