Q. What is the airspeed velocity of an unladen swallow?
African or European?
From The Internet Movie Database (Monty Python and the Holy Grail):
Hee hee heh. Stop. What... is your name?
King Arthur: It is 'Arthur', King of the Britons.
Bridgekeeper: What... is your quest?
King Arthur: To seek the Holy Grail.
Bridgekeeper: What... is the air-speed velocity of an unladen swallow?
King Arthur: What do you mean? An African or European swallow?
Bridgekeeper: Huh? I... I don't know that.
[he is thrown over]
Sir Bedevere: How do know so much about swallows?
King Arthur: Well, you have to know these things when you're a king, you know.