I've always had some suspicions, mainly b/c of my job, but this video just seems to make so many points. It's another 9/11 conspiracy video. If you have about 90 minutes to spare I'd suggest checking it out.
http://video.google.com/videoplay?docid=7866929448192753501&q=loose+change&hl=en
http://video.google.com/videoplay?docid=7866929448192753501&q=loose+change&hl=en