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.
gritter grittier critter grottier garotter grater garter greater crittur grouter greeter grodier gridder greedier cowriter garroter criteria groutier curter krater grader carter crater guarder curdier courter quarter courtier cruddier quartier carrotier carder corder cruder creator crowder curator
fritter critter gritter ritter brattier triter cowriter prettier ratter grittier crittur reutter garotter rotter bruiter rioter writer fretter frettier frotteur fruitier fruiter grottier rattier rewriter ruttier trotter
gritty grit griot grotto grotty