A Great Joke about the Use of Punctuation

I found this joke on a humorous book on the use of punctuation. The book's name is, Eats, Shoots and Leaves. This is a great book on the proper use of different punctuation, peppered with some witty and funny stories. Anyway, the joke reads like this,
  
A panda walks into a café. He orders a sandwich, eats it, then draws a gun and fires two shots in the air.

"Why?" asks the confused waiter, as the panda makes towards the exit. The panda produces a badly punctuated wildlife manual and tosses it over his shoulder.

"I'm a panda," he says at the door. "Look it up."

The waiter turns to the relevant entry and, sure enough, finds an explanation.

"Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves."

So, punctuation really does matter, even if it is only occasionally a matter of life and death.

Do you know any other joke to share about the use of punctuation?