The singer sets the night on fire while performing in Toronto. Plus: Beyoncé & Jay-Z, Shia LaBeouf, Paris Hilton and more

FAN GIRL

Smile! The Hills' newest troublemaker, Kristin Cavallari, gets down with fans Saturday at club mur.mur in the Borgata Hotel in Atlantic City, N.J. The Laguna Beach alum starts her run on the MTV reality show this fall.