@Miburo, mad props to the aliens who're racist against middle easterns :P. The conspiracy theorists that you're referring to are the extreme ones. Those are the ones that are quick to jump to any conclusion that sounds somewhat feasible, which is rather annoying. However, don't let the image of these theorists persuade you to automatically brush off any conspiracy theory. Because there's usually different versions of a conspiracy theory, varying from extreme to logical. And if you brush off the logical theories too quickly (not... sure if there are any anyway), then you're the same as the extremist conspiracy theorists who believe Dick Cheyney is an alien, as you both would be jumping to conclusions too quickly (although, brushing off a theory is much more logical than being super gullible).
Don't get me wrong, I'm sure the goverment hides details of what happened, and I know they're not saints. But in this particular scenario there's a much more logical alternative to "teh goverment did the 9-11 terrorist attacks." And it's that the terrorist did actually do it.
The "Loose Change" video his been debunked rather well already by numerous sources, I can post links in necessary, so I'm just going to ignore that digital chunk of stupidity for the moment.
There's still no intelligent motive for the American government to destroy it's own buildings and kill it's own people. You can say "to make an extremely small percentage of people richer" but that doesn't make much sense at all. There's plenty of other currupt ways to make money that doesn't involve killing thousands of your own people and making a world-wide display of it all, not to mention the fact that it would take a shitload of people to pull it off-all of which would have to keep their mouths shut about it. Let's not forget that an extremist terrorist organization who have both the means and the motives to do such a thing admitted to doing it....
And the cost of cleanup, reconstruction, improvements in security, and training probably offsets a lot of the money the goverment as a whole would've hoped to make. The war itself hasn't been very cheap either.
So I'm not just saying "Nah, that's stupid, the goverment wouldn't do that" without even thinking about it. I'm actually thinking it through using a bit of common sense and coming to the conclusion that this particular conspiracy is pretty stupid for what I would think to be obvious reasons.