Shortest poem ever: FLEAS Adam had'em. (author unknown)

That is a favorite of mine. I did a search on Stumpers-L (which is a email list for librarians seeking answers to obscure reference questions, but you can learn a lot on it) and found it isn't anonymous. It is a poem by Strickland Gillilan called "On the Antiquity of Microbes."

Another contender: "Some Sage Advice from a Confessor to a Lady Of Literary Easy Virtue": O, No! by Peter T. Prunka TGW Computer Solutions

I'd guessed that it was an Ogden Nash poem, but apparently not. Thanks for the ID, dialyn! (If you haven't read Ogden Nash, go look at his stuff. He's really fun to read.)

You are so right. Ogden Nash is a treat. So is Richard Armour and, of course, James Thurber ("are a booby," she said, "and I am going to have you put in the booby-hatch.") Dorothy Parker. There are a lot of writers worth going back and checking out.

Ogden Nash's Carnival of Animals is my all time favourite bit of nonsense. Kangaroos can jump incredible, they have to jump because they're edible. I could not eat a kangaroo, but many fine Australians do. Those with cookbooks as well as boomerangs prefer them in tasty kangaroomerangs.

Sounds a bit like Dr. Seuss. (grin)