Hey! Oliver Wendell Holmes' "The Chambered Nautilus"!
http://www.bartleby.com/102/107.html
I remember "helping" my oh-so-serious older sister memorize it when she was in high school and I was in middle school. She would lock herself in the bathroom to practice her grand gestures before the mirror. Every time she got to the "Cast from her lap, forlorn!" bit, I'd yell through the door, "Who milked the cow with the crumpled horn!" Then she'd come tearing out of there, absolutely livid. She even caught me once, but it was totally worth it. Ah, sweet memories...
I have no time to do anything with it, so anyone else should feel free. It might not be a recognizable poem to the judges, though.