I saw Michael Moore's Fahrenheit 9/11 last night at the Metreon downtown San Francisco. I wanted to see it there rather than in France to find out how an American crowd would react to it. I found the documentary great but the crowd quite atonal (pop-corn crunchers apart). I've seen more expressive reactions to hollywood blockbusters, and that is a bit disappointing. Though, there were several moments when people (inclujding myself) were crying. I'm going to see again in France to compare.
You should see it too, and if you don't want to shell a few bucks to Moore, well, he won't go after you if you grab it for free on the Internet.