I was gonna post the Nantucket one, but Alex beat me to it. Here's another...

There was a young lady from Clare Who possessed a magnificent pair Or so we all thought Till her left one got caught On a nail and began losing air.

and a clean one...

A tutor who tooted the flute Tried to teach two young tooters to toot Said the two to the tutor, "Is it harder to toot,

ScottyG Or to tutor two tooters to toot?"