A flying saucer landed at a gas station on a lonely country road in New Mexico. The letters "UFO" were emblazoned in big letters on the side of the craft. Two bug-eyed aliens stepped out and while the gas station manager stood paralysed with shock, his young blonde assistant nonchalantly filled up the tank and waved to the aliens as they took off again. As they disappeared into the sky, the station manager turned to the blonde and said: "Don't you realize what just happened?" "Yeah," replied the blonde. "So what?" "Didn't you see those two?" persisted the manager. "Yeah," said the blonde, shrugging her shoulders. "So what?" "But didn't you see the letters 'UFO' on the side of that vehicle?" "Yeah. So what?" "Don't you know what UFO stands for?" The blonde rolled her eyes. "'Course I do, I've been working here five years. UFO stands for 'Unleaded Fuel Only'."