And quickly debunk them!
http://www.snopes.com/rumors/wingdings.asp
Whoo, Snopes!
Here's a few I've heard over the years (but obviously do not believe):
-Pokemon cards were incredibly popular because kids were addicted to a secret nicotine coating on them (there are so many jokes about this one I don't even know where to begin).
-The center of the Earth houses a secret civilization of whatever (still... you've got to admit that we really have never
looked that deep...).
-We never went to the moon (a ridiculous conspiracy, but the motives would make perfect sense).
-The reason we couldn't find any WMDs in Iraq (or wherever) is because they're invisible--the US sold cloaking technology to Saddam Huessein when we were still on good terms.
-Anything about dead celebrities/presidents (Kennedy, Marilyn Monroe, Lincoln, James Dean, Elvis...)