The singer dances up a storm during a Today show performance. Plus: Britney Spears, Halle Berry, Bruce Willis, and more

CHILLER THRILLER

Josh Hartnett braves the frigid New York temperatures Thursday, all in the name of art – he's in town filming the mistaken-identity thriller Lucky Number Slevin. The actor will next be seen – fully clothed – in the crime drama Sin City, due out April 1.