Gossip Girl's Leighton Meester claims to have little in common with her scheming TV alter ego, but at Piaget's launch of its Limelight Paris-New York Collection on Thursday night, she did prove to have Blair Waldorf's eye for dramatic entertainment venues. "This would definitely work as a show location," she said as she surveyed the Rockefeller Center garden rooftop. "Who doesn't love a pool and a lawn in Manhattan?" Her pal Emmy Rossum had a more intimate affair in mind. "I could get married up here," she said. "Although it's weird that I'm even thinking of wedding venues—I'm 21." Back inside, a glittery-in-its-own-right crowd that included Liv Tyler and Maggie Gyllenhaal mingled with models draped in Piaget diamonds. So impressive were the rocks, the girls didn't mind the attention drawn to their décolletés. Said one, "For once I know they're not gawking at my chest."

— Derek Blasberg