A man phones a mental hospital and asks the receptionist...
A man phones a mental hospital and asks the receptionist if there is anybody in room 27. She goes and checks, and comesback to the phone, telling him No, the room is empty. "Good," says the man. "That means I must have really escaped."

747 Full of Lawyers
Q: Hear about the terrorist that hijacked a 747 full of lawyers?

A: He threatened to release one every hour if his demands weren't met.