The Glenn Beck Conspiracy Theory Generator (all GB, all the time)
Compose Your Own Conspiracy Theory (features liberal, neoconservative, and Jewish themes)
Conspire: Discover (fill in the blanks with people and ideas you think are stupid!)
This is great stuff if you write for magazines like Weird Tales, Southern Fried Weirdness, Aberrations, or other interstitial arts. If the original theory isn't weird enough, just toss in some zombies, aliens, vampires, or a lake monster. That should do the trick. Happy plotting!