To say this movie is useless isn't quite right. I can think of one purpose: tell your friends to watch it and have them tell you what they think. If they come back and tell you "Wow, this was amazing; it opened up my eyes; the gov't did 9/11", then your friends are either A) idiots, or B) dishonest... in either case, this movie is an incredibly effective tool to let you know who not to bother hanging around.
Boy oh boy... factual error after factual error... outright lie after outright lie... pissing on grave after grave of 9/11 victim... The fact that this horse feces is sweeping the nation's college campuses completely makes me lose any faith in higher education and proves to me only that far too many college kids prefer spooky techno music to silly boring things like research and the desire to find reality.
So yeah, other than that handy little intelligence test, Loose Change is completely useless. Read Mark Roberts's Viewer Guide; it blows to hell every single point LC tries to make and calls them on every single error. http://www.loosechangeguide.com/LooseChangeGuide.html