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.
criteria critter cowriter curter carter crater courter gritter crittur curdier grittier courtier cruddier carrotier corder carder garter krater cruder grater grouter quarter greeter greater curator crowder gridder creator grodier creature garotter garroter greedier grottier groutier corridor quartier grader
criteria veratria moratoria trattoria
crit caried carte crate cried curite scried