The person I heard this from ("Al" in the story) swears that it really happened. (And no, I'm not this "Mark" - you should be able to figure out why I chose those names. :)
Two guys (we'll call them "Mark" and "Al") are out cruising. Mark is driving, and they're on some out-of-the way roads. Mark is distracted and doesn't see a stop-sign, and a few moments after he runs it they hear a siren and see blue lights. Mark has never been stopped by the police before, and gets really nervous.
MARK: OhshitwhatdidIdo? I wasn't speeding, was I? No, I wasn't speeding. What'd I do what'd I do?
He pulls over, shaking like a leaf. The cop pulls in behind and walks up to his window.
COP: You realize you ran a stop sign back there?
MARK: [panicky] No, honest! I didn't see it! I didn't mean to run it! I just didn't see it! Really!
COP: I'll need to see your driver's license.
Mark pats his pants for a few seconds before remembering that he's wearing shorts with no pockets. He looks around the car, finds his wallet, opens it up, and starts frantically throwing things out of it into the back seat. No license. He enlists Al's help, and together they search the glove compartment, under the seats, behind the cushions, front and back, to no avail. After ten or fifteen minutes of searching, Al looks up and catches the officer's eye.
AL: You don't need to see his identification.
COP: [without missing a beat] I don't need to see his identification.
AL: These aren't the droids you're looking for.
COP: These aren't the droids we're looking for.
AL: He may go on about his business.
COP: You may go on about your business.
AL: Move along.
COP: Move along.
At this point the cop turns around, walks back to his car, gets in, and drives away.
Mark pulls out and makes it about 200 yards down the road. Then he stops and just shakes for a few minutes, finally asking Al to drive.