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.
peen pen peon pean pein paean peony paeon penny penne penni penna pennia pawnee pennae pan pin pun pine piny pony pone pain pian pawn pion pane poon pina puna puny panne piano piney pinna pinny punny
been keen queen peen seen teen ween wheen sheen en