Best:
A young woman was pulled over for speeding. As the motorcycle officer walked to her car window, flipping open his ticket book, she said, "I bet you are going to sell me a ticket to the Highway Patrolmen's Ball."
He replied, "Highway patrolmen don't have balls." There was a moment of silence while she smiled, and he realized what he'd just said.
He then closed his book, got back on his motorcycle and left. She was laughing too hard to start her car for several minutes.