Best suggestion of the thread...
Hear in the news how people are going as Osama this year. It only makes sense if there is a good partner costume.Missles, etc. work but aren't as classic as this pairing.
Tourist guy is good but I don't think enough people are in on the joke. A better idea would be if the party host had a mockup board of the first tourist guy photo with the head cut out so party guests could put their face in the picture...