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.
caucus cacas cacaos caiques cuckoos cakes cocas cocks cocos cukes gucks kagus cocoas
fucus caucus mucus chucks ducks sucks rucks raucous locus mucous nocuous lucks gucks cues cuss ficus yucas bucks ecus focus fucks shucks tucks vacuous dioicous fugus ruckus recuse hocus mucks pucks jukus fucous jucos hucks yucks