Mamma Mia! was not meant for the stages of Broadway, it was destined to be made into a movie for screening at Dolores Park. It’s got singing babes and a James Bond wannabe. Clearly Mamma Mia! was made for Dolores Park viewing parties.
Remember, screenings start shortly after sundown, but arriving early to stake out a spot is always advised. Blankets, pillows, backrests and low chairs are all welcome, but Film Night organizers suggest you leave your pets at home even though you're totally going to bring Fido anyway. More details here at the SF Neighborhood Theater Foundation: http://www.sfntf.org/
Dolores Street b/w 18th and 20th Streets Map