Kardashian works her hips with a hula hoop at an Old Navy event in Los Angeles. Plus: Mary-Kate Olsen, Nicole Richie, Rob Pattinson and more

WALK THIS WAY

Mary-Kate Olsen has a rosy (and rock 'n' roll-inspired) perspective at the premiere of The Hangover Tuesday at Grauman’s Chinese Theatre in Hollywood. Also at the premiere, the starlet's sister, Ashley (not pictured), whose boyfriend Justin Bartha stars in the comedy.