Olsen turns out for a rockin' rooftop party in New York City. Plus: Gwen Stefani, Prince Harry, Shannen Doherty and more

HOST WITH THE MOST

English actor-comedian Russell Brand has gone Hollywood – literally! The host of this year's MTV Video Music Awards happily poses with Christina Aguilera and rapper T.I. during a news conference to preview the upcoming awards show, which airs Sept. 7.