Who knew that San Fran has a catamaran charter available for anyone. For a relatively nominal fee, you get 1.5 hours of sailing around the bay. You see many of the icons of San Fran, all while enjoying a novel way to ride the high seas. Fun times for all, if you can stay warm, dry, and get your sea legs under you.
I can't think of a better $40 I've spent in the last umpteen years. I'd highly recommend you look into this if you're in San Francisco, setting sail right off Pier 39 on their famous Fisherman's Wharf.