Even movie stars know who's Boss. "His music is poetry in motion," offered Lara Flynn Boyle before Bruce Springsteen's Aug. 18 concert at Las Vegas's Thomas & Mack Center. "And no one wears jeans as well." "Which is saying something among this crowd—including Robert Downey Jr., Cindy Crawford and Christina Applegate—who boogied to a 2½ hour set that included a cover of Elvis Presley's "Viva Las Vegas," then rocked on at a VIP party hosted by the Hard Rock A Hotel and Casino. "I heard a rumor he's wearing khakis and Lacoste now," Saturday Night Live's Chris Kattan joked before the show. But I reveler Frances Fisher confirmed that the chart-topping Boss (clad in black denim) is still in his glory days: "I've been at almost every tour. He hasn't changed a bit." And yes, Lara, "his booty's still cute!"