Perhaps this is a little off color, I long ago lost any ability to determine what is or isn't appropriate, but I always thought it was funny.
A man (who had clearly already had a few) stumbled into a bar, and shambled up to the barkeep. He leaned in close over the bar and, a worried look on his face, asked, "Hey! You know anythin' bout penguins?"
The bartender replied, "No man, not really."
The man, still looking quite concerned, said, "Well, well ya know if there're any penguins zat're five feet tall?"
The bartender gave the man a curious look and said, "No, no I don't think so."
Clearly quite distressed, the man leaned even further over the bar and asked, "Ya shure?"
The bartender said, "Yeah I'm pretty sure."
The man wailed and slammed his head onto the bar, "Ah Jesus tap-dancing Christ! I just ran over a nun!"