Last night's annual Serpentine Gallery Summer party brought out a who's who of Londoners. Designer cohost L'Wren Scott welcomed Kate Moss, Princess Beatrice, and even one of the Middletons to enjoy art and the pretty London evening. Jimmy Fallon made a special appearance, as did his fellow New Yorker Sarah Jessica Parker! We have the whole scoop on the fun night, which Kate and Naomi Campbell kept going with a stop at the Dream for Future Africa Foundation's dinner — and they didn't turn in until early this morning! On Allie: Dress and Blazer by Reiss.