Efron covers his signature shag do with a knit hat while out in Burbank, Calif. Plus: Kristen Stewart, Johnny Depp, Gisele Bündchen and more

JUST FOR LAUGHS

What a joker! Reese Witherspoon finds her funny bone alongside her equally amused costar Paul Rudd while filming a scene Tuesday for their comedy, How Do You Know, in Washington, D.C..