http://en.wikipedia.org/wiki/911_Conspiracy
Above is the link that has some answers to common BS. I have seen better research, but I don't have those links here.
There are things so wrong with that movie, I don't have the strength to talk about them. Pictures that show one thing and the narrator says its something else, or blatantly incorrect scientific information, such as the temperature at which metal will melt.
Also some of the sources they used in their research are tainted from the get go. One of the first and loudest conspiracy theorists is a neo-Marxist, deeply anti-American French "journalist" who really speaks for himself when you read his stuff. He writes for Voltaire...something-o-r other association (he is founder). So when these dweebs say they researched a lot of information, a lot of it was his.
--Funny side note: He also claimed Game Theory was developed by Talmudic Jews to mathematically justify their abuse of Palestinians (this is almost a quote) ... see his article on criticism of the Nobel Prize for Economics.--
Is our government like all governments self-serving and corrupt? YES. But what bothers me about this kind of misinformation is that it takes our attention away from the real enemy that makes this self-service and corruption look like child’s play.
We have an enemy that commits terror over the world for many decades. They committed these acts before and after this particular event … time after time after time. Is it then so unlikely that THEY might be responsible for this?