Three men hail a taxi. The driver- seeing that they're drunk- decides to pull a fast one. So he switches the engine on, then quickly switches it off and announces, "We're here!"
The first guy hands him the fare, the second guy says, 'Thanks," but the third guy angrily smacks the cabbie's head.
"What was that for?", asks the cabbie, afraid he's been caught.
"That," says the passenger, "is for driving so fast!"
Hat tip: Rajagopalan of Just Out