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.
rewriter reorder
writer rewriter cowriter triter charter fritter rater garter barter fruiter critter artery arider ritter rioter joyrider rider hardier hurter shirtier quarter artier purtier lardier narrater parroter pearter porter sorter derider tardier tartier heritor wartier gritter courter dirtier fruitier ureter tarter curter bruiter ferreter curdier garroter heartier horrider irater frater carter chertier torrider wordier courtier darter grater krater quartier lowrider nerdier partier perter prater crater barrater shorter