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.
garter garotter garroter grater carter grouter greeter quarter gritter greater guarder grottier quartier grittier groutier carder crater grader carrotier curter krater critter gridder grodier courter criteria courtier greedier cowriter corder cruder crittur crowder curdier creature cruddier
barter garter sorter hurter pearter quarter carter darter curter shorter porter courter perter tarter charter frotteur rooter cowriter fruiter narrater artier hoarder order mortar fretter harder fruitier rewriter rootier carrotier grittier frater rattier prater rioter purtier fritter rater dirtier chertier charioteer wartier ureter trotter treater bruiter retear reutter martyr courtier critter ferreter writer carder garroter partier murder ritter tartar artery barrater brattier boarder quartier heartier krater greeter grater ruttier birder girder gritter border rotter crater corder grottier greater sartor larder brighter irater grouter ratter garotter herder frettier guarder prettier parroter shirtier reorder groutier tartier triter troutier warder weirder router yarder
cart garrote guard grotto grot gritty grit grate grat garrotte garret carte garred garotte garote gardai garda grotty kart