The hottest trend in yoga? Not paying if you don't want to. Donation-based yoga's been around for a while (check out this April article in the New York Times on the trend) and has swept many Bay Area studios with its come-one-come-all mentality. 

Rusty Wells, local yoga-master (he's got a cultish following) and recent Wanderlust Festival instructor, just released the first of a video series explaining the ethos behind his donation-based Urban Flow Yoga studio.

Urban Flow Yoga: How This Came To Be from Urban Flow Yoga on Vimeo.

Classes work on a suggested-price system so anyone without extra cash can get in on all that stretching, posing, and downward-dogging. Are you through turning up your nose at yoga yet? Here are a few studios in the city and across the Bay to get you started at:

Yoga to the People, in both Berkeley and San Francisco, has a suggested donation of $10, but nothing's mandatory. It's known for its unpretentious atmosphere, and every class is open to all levels of yoga awareness. 2973 16th St., (917) 573-9642

Laughing Lotus Yoga Center's curriculum isn't all donation-based, but they do offer Vinyasa "community classes" every week day taught by new yoga teachers. You can attend these classes at either the Laughing Lotus studio or at the Women's Building at 3543 18th Street. Donations from these classes benefit the Women's Building. 3271 16th St., (415) 355-1600

Bikram Yoga in the Mission is in the heart of the Mission, and has a separate, sunny studio just for donation-based yoga and other movement classes for both beginners and seasoned yoga-philes. They offer all kinds, including Hatha, Vinyasa, Acroyoga, and men's and women's naked yoga. 2390 Mission St., (415) 401-9642

Yoga on the Labyrinth takes place in the gorgeous, tranquil Grace Cathedral every Tuesday at 6:15 pm. Often they'll have a live musical guest to accompany the session. All donations go to the church and live musical guests. 1100 California St., (415) 578-3377

Where do you do donation-based yoga?