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.
poon peon pone pony pion paeon peony pen pun pin pan hyponea pein pine pean pina pain piny pawn puna pian puny hyponoia peen pane penna penny penni piano pinny pinna piney panne paean punny penne
boon coon goon loon moon noon poon soon zoon toon shoon on