It's an old American hand sign meaning "Good Luck". At least that's what the crew of the Pueblo("Penetration, however slight, is sufficient to constitute the crime") told their North Korean captors.
Update:
I noticed, in the trackbacks to the linked post, a Kerry supporter equating this to Bush-hating obscenities. I don't think it is the same, and wouldn't have shared it if I did. The symbol has specific meaning within the military, and the blogger who shared the image has very close ties to the military. I can concur with the lack of respect our fighting forces have for a man who could portray himself as a war criminal or a war hero when it suited his purposes without giving him a little birdie in other circumstances.
Posted by triticale at January 21, 2005 08:02 AM