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.
caste cast caseate casette cased coast cassette caused costae casita coesite cassata cost gast coset costa cosied cosset cuesta cussed gassed gaseity gazette quayside gust kist
baste chaste taste waste haste caste paste ghast wast past ceased pasty listee sayst costae sate east misate caseate maist cast roast roseate hessite beastie nauseate yeast geste testee teased rased resite eased toasty lased beast fast feased biased fissate testae hast chased bast coast cased phased saute mustee stey mayst hasty mast moste coesite pastie zoisite leased site vestee piste oast postie boast based vast mestee lysate fossate last least nasty vasty feast pasta toast waist tasty gast stew yeasty
casa case cassia cause causey caws cays ocas