I read a good article on photo permits that Scott Kelby from Photoshop Insider posted. Here in San Francisco we do a lot of location shoots so we’ve come across this. If you are shooting in a Parks and Rec property then you do need a permit. The fees and such are all outlined on the City and County of San Francisco’s website including the minimum fees. My favorite thing is the “Did you know…” section listing some of the films made in San Francisco parks like The Rock and Star Wars.