It's always a good sign when your yoga teacher has a six-pack. At Urban Flow, the yoga masters will whip you into shape physically and mentally. Yoga guru Rusty Wells took his growing followers and recently moved from the Castro to the hip urban warehouse building along Mission Street. True believers of helping people feel enlightened (or at least lighter), Urban Yoga will never turn you away, even if you don't have the money. There is a suggested donation of $10 to $15 per class.