If you missed last year's Chilibowl at Potrero del Sol, it was 'fucking tight' and definitely worth checking out this year.  To quote what I wrote about the occasion last summer:

The Chilibowl was an incredible way to squander away a Saturday afternoon: water balloons full of beer, a blood geyser coming out of a guy’s head, filthy jokes from the announcers, a punk band playing awesome songs like “you are dead, motherfucker” and “crack on Mission St.” within a few dozen yards of a playground full of children, and, of course, skateboarding.

That's right, not only is the Chilibowl full of shittalking and blood, it's at Potrero del Sol, which is just like Dolores Park without the cops, trash and whiny neighbors.  If you want to get psyched up for a good time, check out this crappy iPhone video I shot + edited last year with some weak-ass Dan the Automator track dumped on top of it:

If skateboarding sounds like too much fun and you'd rather do more of the same old shit, a bunch of local businesses are shutting down 18th from Dolores to Guerrero so you can drink wine and eat food on the pavement near Dolores Park, as opposed to the urine-soaked grass you usually enjoy.  (link)