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.
combat comate commata comet comte comity commit combed comade commute coembody committee comedo comedy gambit gomuti commode gambade gambado gumboot gummata
combat numbat wombat mat teammate lambda tomato commata summate comate roommate gemmate ramate mammate humate mammati limbate gambit somata hamate lemmata ambit moat meat maut matt mate gummata bumboat remate bemata
comb combe combo cambia coma comae come comma commie commy coomb coombe cumbia gombo kombu