You know I tell you to travel a lot. I'm always harping on everyone to "seize the day" and "live it up" and "go while you can!"
I stand by that. However, if you DO decide to take off to a foreign land, it's always a good idea to do research on the local customs before you go. And to help you out a bit, here's a lovely INFOGRAPHIC from Coolinfographics.com!
Pretty interesting, right? Look into common offensive gestures for the place you're going, just to make sure you don't end up offending the locals!