This one comes to mind, especially with what's going on in Iraq. My father was in California, probably Travis, picking up a load of marines headed for Viet Nam. He was in the back of the aircraft when he spotted a young marine -- who couldn't have been older than 18 and looked like a surfer from the area -- with a skate board.
He looked at him and said something like, "I don't think you know where you're going, you won't have much time for that thing when you get to Viet Nam. If you don't stow it properly someone will get hurt if we hit turbulence." Giving the guy a hard time just to give him a hard time.
Only one week later, he was back in country. The flight back to the states was an air evac mission. My father walked up on the plane through those clamshell doors headed for the flight deck. He heard someone holler out for him. When he looked up, there was that same marine. He was already headed back stateside with both legs missing.
My father never gave those guys a hard time after that.