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.
undoer under undraw undrew uniter untrue unitary
undoer gender fonder tender cindery condor bendier bindery hounder bounder handier bandore lender minder bender funder fender pandore lander vendor meander binder wonder winder tindery denuder reindeer endear rounder maunder pounder dandier pinder bonder snider candor sounder keynoter zander pandoor sandier sender mender pandora pandour finder vender bandora pander kneader needer needier joinder indoor noter bander gander sander tinder founder launder hinder hander randier dander kinder sunder candour sonder nodder ponder daunder wander nuder cinder ender render tandoor under windier yonder
undo unde undee undue undy unto