I wasn't actually present at these protests today (Friday, March 14, 2003), because I'm still in Austin, Texas, but I was able to find a link to some video footage, a legal report (which cops did what to whom),
pictures, and a summary of the details on the Indymedia website.

Protesters Shut Down Stock Exchange, Blockade Bush & Market
3/14: Some 80 protesters were arrested this morning in downtown San Francisco taking part in an emergency direct action to prevent war in Iraq. Direct Action to Stop the War has been organizing "day-after" actions for the business day after war starts, but many felt the need for a "preemptive strike" to stop war before it starts.

Over 200 demonstrators gathered at dawn at the old Pacific Stock Exchange building at Pine and Sansome. Several speakers rallied the crowd, including student, queer, labor, faith, and people of color activists. Some protesters formed a blockade outside the financial trading floor, while others blocked the intersection of Bush and Montgomery. About 30 sat down in the street, chanting "We are blocking Bush!", and were arrested around 8:30am after police gave a dispersal order. Protesters continued down Bush Street to Market, where two separate groups blockaded the street and were also arrested and loaded into sheriff's buses.