"The Telegraph" , a British newspaper, has published a book showing rude hand gestures from around the world.  Flipping the bird doesn't translate across the globe, so if you plan on traveling this is a good way to know how to tell someone off.  They are all very interesting.

Moutza:  In Greece, if you extend your hand toward someone, palm out with your fingers spread.

Idiota:  If you want to call someone stupid in Brazil, hold your fist against your forehead, and make an exaggerated overbite.

Five fathers:  Pinching the tip of your index finger with all five fingers of the other hand tells people in Saudi Arabia that you think their mother had several sexual partners.

--Corna:  The "hook 'em horns" or heavy metal devil horns gesture means "your wife is unfaithful" in Portugal, Spain, and Brazil.

--The Write off:  Touching your fingertips together, and making a V with your hands in front of your belly button tells people in Greece you're ignoring them by . . . pointing to your genitals, basically.