Zach Galifianakis: Live at the Purple Onion

From an inauspicious beginning performing comedy routines in the back of a burger joint in New York, unorthodox stand-up star Zach Galifianakis has made a splash on the scene with his inimitable brand of humor. In this live show filmed at San Francisco's Purple Onion nightclub, the versatile funnyman serves up a health…