Today’s the annual San Francisco version of Carnaval — always the Sunday of Memorial Day weekend, since its traditional Mardi Gras date happens in February when the weather is likely to be horrid here — featuring squads of be-feathered dancing girls and boys cavorting and shimmying down Mission St. It’s a great parade, if you’ve never seen it. And if you miss it, just check Flickr in a few hours. (Update: try the 2008carnaval tag.)

Also today, conveniently beginning a few hours after the parade of nearly-naked people: the annual Masturbate-a-thon, a benefit for the Center For Sex and Culture. It starts at 3:00 pm, features live performances by real porn stars, and is open to all persuasions. Interestingly, it costs $20 to participate — and $40 to just watch.