Well, it turns out that some idiot French actress who just won the Academy Award for her Edith Piaf portrayal believes -- hold on to your hats here -- that 9/11 was perpetrated by American business interests because "it was less expensive to demolish" the towers than it would have been to perform needed structural upgrades. I am not making this up.
Here's the "Inconvenient Truth" that the 9/11 nutjobs on the Internet need to learn -- on September 11, 2001, 19 Arab men hijacked four commerical, domestic flights and rammed those planes into three buildings and one field. The U.S. Government did not 'invent' these people. All the 9/11 hijackers (plus Zacarias Moussaoui) lived well-documented lives and received well-documented training before, during, or after their process of radicalization.
The 9/11 attack was masterminded by a man named Khalid Sheikh Mohammed. He is a real guy who is really the uncle of Ramzi Yusuf (First WTC attack planner, also a real guy who is really sitting in the real Supermax in Colorado). KSM was also a close associate of Ramzi bin al-Shibh, a Yemeni who was also involved in the 9/11 planning and organization.
You can read about all of these individuals via the copious amounts of open-source literature easily available at your local Barnes & Noble or Borders. You can read about their ideologies, their education, family background, etc. You can read about the exact details of their plans as they unfolded. You can learn about Operation Bojinka and several other of their plans. You can do this by reading books written by Americans, Brits, Pakistanis, Afghanis, and numerous other authors -- none of whom are employed by Dick Cheney or Halliburton or Unocal.
But that would take effort! Think about all the hours that would cost you, let alone the cost of the books and articles themselves! That doesn't sound like any fun. Just think about how much easier it would be to watch one or two misleading Internet films that spout pseudo-intellectual babble like the ponderous rhetorical question, "Who benefits?" You can use one corner of your mouth to talk about government incompetence and stupidity (after all, a person of your intellectual grandeur would never work with those plebeians), while using the other corner of your mouth to talk about a bizarre science-fiction fantasy that would literally have required thousands of talented operators, somehow all sworn to secrecy!
If you're interested in learning what really happened on 9/11, all the information is out there.
But why make the effort?