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.
cruddier cruder curdier carder corder critter grodier crowder gridder criteria groutier courtier cowriter greedier carrotier crater grader carter curter creator crittur gritter grouter courter guarder grittier grottier corduroy creature corridor quartier garter grater krater
ruddier cruddier wordier prodder readier redder reedier ridder rowdier rudder broodier hardier curdier greedier gridder grodier lardier nerdier tardier shredder