It's no secret to those I know that I detest Michael Moore. In fact, I've vowed that not one single cent I earn will ever go to support the man. His treatment of the facts in Bowling for Columbine (and Scott's posted links to those sites, check the archives) is, IMHO, basically criminal.
However, I haven't found, until now, a good rebuttal of F911. Now, I'll admit, I'd like to see the sources quoted on this guys facts, but he makes several very good points. If you read between the lines, you'll see that this isn't a documentary - it's propaganda.