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.
carpal carpale carpalia carpel carpool crapola cripple creepily croupily grapple graupel gripple
carpal repeal hirple carpale carpel purple purply troopial troupial sharply
carp carpi crap crape crappie crappy crepe crepey crepy cripe crop croppie scarp