Wikipedia offers a thorough discussion of conspiricism and a long, annotated catalog of conspiracy theories that have been popular at one time or another. The final theory in the catalog goes a long way toward explaining the present state of affairs. It also justifies the use of the somewhat controversial term "Islamic fascists." Here it is:
Islamic-Fascist Axis
Radio talk show host David Emory claims that Nazi leader Martin Bormann never died and has built a global empire involving, among many others, the Bush family, Hassan al Banna, Grover Norquist, Meyer Lansky, and Michael Chertoff. This may have sprung from the factual World War Two alliance between Nazi Germany and the Grand Mufti of Jerusalem, a religious and political leader of the area then known as Palestine.
There's a conspiracy theory for you: a Nazi, the Bushes, an Arab-Muslim extremist, an anti-tax conservative, a Jewish gangster, and a Jewish lawyer-prosecutor-cabinet secretary.
I can't wait for the movie.
P.S. On a serious note, check out this piece about the "9/11 "Truth" movement.
P.P.S. In the same vein, there's this at RightWingNutHouse.