Bike messenger Joseph Gordon-Levitt doesn't believe in brakes (kinda like Sid Haig from PIT STOP) or newfangled bicycle technology like gears or lightweight frames. He's like the Amish of bicycle technology. Instead, he just pedals his ass off and uses backwards pedal movement to avoid cars. One day Joseph is called to deliver an envelope to Chinatown, but before he can get even two feet a crooked cop comes along and starts hassling him. Joe takes off and the cop chases him all over town. That's pretty much the whole story.
Not surprisingly, PREMIUM RUSH isn't great cinema or anything deep. It's just mindless entertainment with a bunch of flashy images, chase scenes, video game/music video styling and hip references that'll mean nothing in a few years, but...it is entertaining and that's all that matters. Did I like it? Yes. Will I ever watch it again? No.
Good for a one time watch.