http://en.wikipedia.org/wiki/There_once_was_a_man_from_Nantucket

"There once was a man from Nantucket" is the opening line for many limericks. The popularity of this literary trope can be attributed to the way the name of the island of Nantucket lends itself easily to humorous rhymes and puns, particularly ribald ones. In the many vulgar versions, which were not published until many years after they were well known, the protagonist is typically portrayed as a well-endowed, hypersexualized persona.