It's pathetic that it's even necessary to debunk such a blatantly hysterical and racist rumor, but I've heard from too many people rattled by an email claiming Barack Obama is a radical Muslim who refuses to observe the Pledge of Allegiance. The viral email slur cluttering inboxes everywhere expresses dismay at how the Senator from Illinois threatens to sneak into the White House for the glory of Allah.

I understand why amoral political enemies would wage this kind of attack, but I'm not sure why are so many of us are eager to forward these lies on to others without considering the source.
My recommendation? Run it by snopes.com for a reality check. Most every internet urban legend I've encountered is examined there. Snopes may not be an all-knowing oracle, but the authors appear to be relatively diligent and impartial.
Maybe that's the genius of these misinformation campaigns. The claims are so absurd that the mainstream media never bother to debunk them.