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.
charter charioteer chertier shorter shirtier shredder shrewder
barter pearter carter tarter quarter darter charter garter ureter curter tartier wartier ferreter courtier crater garroter harder purtier artery warder narrater krater frater hurter perter prater rewriter heartier chertier cowriter shorter partier shirtier parroter martyr greater carder courter quartier ratter tartar guarder treater writer dirtier artier triter boarder larder irater barrater porter sorter grater hoarder sartor rater yarder
chart chaired charade chard chared chariot charity charred chert cherty echard