Erratum

Er, I Googled "Sarah Palin bikini assault rifle" after writing the last comment and found both the pic and this report from the L.A. Times, which I would call a credible source:

"Those Sarah Palin photos that were all over the Web on Wednesday, with the GOP vice presidential nominee in an American flag bikini, brandishing a rifle and a big open-mouthed smile that looks semi-loony given her get-up, have been debunked on David Emery's Urban Legends blog. Emery traced the body in question to a Georgia flickr user's account. Palin's head was photoshopped in."

I suppose the scary thing is that it seems like a pretty believable photograph.