I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
pun puna puny punny pen pan pin poon piny pane pein pina pawn pony pine peen pian peon pean pone pain pion paeon peony panne piano pinny piney pinna penny paean penne penna penni pawnee pennae pennia pinnae