A friend of mine saw some of this in San Fran last Saturday.
Held on September 8, 2007 -- just before the sixth anniversary of the 9/11 attacks -- San Francisco's "9/11 Truth March" wended its way through the city's Haight-Ashbury district and Golden Gate Park to the "Power to the Peaceful" festival in the park's Speedway Meadow. The goal behind the 9/11 Truth March was to raise awareness that the events of September 11, 2001 were either a hoax, or were carried out by George Bush and Dick Cheney and their minions, or were a planned demolition by neocon warmongers to create an excuse for starting a war, or were a mass hallucination, or something along those lines. The "Power to the Peaceful" festival is a combination all-day music concert and political shindig that has become an annual event. Blending "progressive" music, radical rhetoric, and revolutionary politics, Power to the Peaceful attracts tens of thousands of revelers and activists.
Plenty of pictures here.