Hope it hasn't already been posted.
A Juggler, driving to his next performance, was stopped by the police. 'What are those knives doing in your car?' asked the officer. 'I juggle them in my act.'
Oh yeah?' says the cop. 'Let's see you do it.' So the juggler starts tossing and juggling the knives. A guy driving by sees this and says, 'Wow, am I glad I quit drinking. Look at the test they're making you do now!'