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.
ripost riposte ripest reposit rapist repast reposed ropiest roupiest reopposed rapacity rapeseed repassed
ripost post pst repast upset rapist deposit papist riposte ripest reposit heppest hippest bypast psst posit pest past deepest typist cheapest
repos repose repousse ripes rips ripsaw cripes gripes grippes grips drips tripes tripos trips