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.
proton parton protean protein pardon partan peritonea hypertonia pertain preteen puritan preattune pardine predawn pyridine
croton proton triton ratoon cartoony cartoon carton carrotin carotin cardoon bridoon burton ratton bradoon baryton baritone rhyton rattoon craton crouton parton barytone lardoon tortoni tritone
protea protei sprout prutah parodoi parody part party pert pirouette port prat prate pretty prod proette proud pruta purty uproot