Once a year, L.A.'s freshest up-and-coming faces gather in the name of fashion at Teen Vogue's Young Hollywood Party. Starlets like Zelda Williams stepped out in a short, sheer black dress by The Row, while Emma Roberts opted for length in a lavender floor-grazing gown, and Lily Collins went for bold pink with Michael Kors Collection's Tulip Silk Dress from the Prefall collection and a gold python barrel clutch. The magazine's Eighth Annual celeb-studded bash also drew out some familiar names this weekend—Kelly Osbourne showed off her killer body in a perfectly structured black mini-dress, while our favorite fashionista Alexa Chung manned the DJ booth (wearing Michael Kors Organic Lace Skirt from the Resort 2011 collection). Take note of these rising stars, because we're guaranteed to be seeing them for some time to come. (Vogue)