Why is giving someone the middle finger a derogatory gesture?
Apparently, the middle finger has long been considered a phallic symbol in many cultures, possibly because it is the longest of the digits. Displaying it to someone is an insult of the first degree, though the gesture seems to be one of aggression rather than sexuality. According to a contributor on the always interesting Urban Legends Archive, the upright stab of the middle finger represents "phallic domination/hostility."
Despite the popular and widely circulated story that the gesture comes from the 1415 battle of Agincourt, this ultimate insult actually dates back as far as to ancient Greece and Rome. The first written record of someone "flipping the bird" comes from the writings of Aristophanes, who spoke of it in "The Clouds," a play from 423 B.C. The Romans even had a special name for the middle finger -- they called it digitus infamis (infamous finger) or digitus impudicus (indecent finger).

Though the interpretation of the gesture varies from country to country, it is fairly widespread. In England, one might display either the middle finger solo, or the index and middle finger together (with the palm facing inward) to convey the same message. And in a recent court case in Japan, a judge ruled, "The sign of raising the middle finger with the back of one's right hand down is recognized in Japan as an act signifying insult or provocation, although it is not as common as in the U.S."

These days, the gesture is becoming more commonplace and is danger of losing some of its "badness." Witness all these celebrities famously giving the finger. It seems even squeaky clean pop princess Britney is not above displaying her longest digit. What is the world coming to?