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.
laterad laddered laterite lettered literate literati littered loitered leotard
laterad trad jittered catered cottered guttered lettered loitered gettered metered neutered muttered petered puttered reuttered teetered tittered uttered watered chittered shuttered outtrade buttered fettered nattered bettered battered triad tread trade littered bittered mattered mitered outread pattered pottered retread tattered tetrad tottered waitered chattered shattered yattered
later lader latria latter liter alter elater plater slater