Sutro Project / Gay Pride Weekend
Often referred to simply as "Pride" and possibly the biggest annual party in San Francisco - Gay Pride makes other "political parties" seem pasty and gray, and the transcendence of oppression into a massive for-anyone great-vibes party is simply remarkable.
Pink Saturday and the Dyke March fall on Saturday, with the parade and party on Sunday. The parade itself is the largest in Northern California. Check the website for more smaller related events, or just wander around until you find something good.
2010 featured the Backstreet Boys, following in Lady Gaga's 2008 footsteps :)
Website: http://www.sfpride.org/
Wikipedia: http://en.wikipedia.org/wiki/San_Francisco_Pride
