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.
gross grass grows cross grouse kaross crosse guiros grassy gars cress gurus gaurs crass grays greys gorsy guars goers gorse grees gores crows grues crouse cressy karoos kouros greasy grease caress crissa curios cuirass gurries carious carouse curiosa curious karroos carassow curassow cars cors cris crus curs kirs kors kris
cross pross dross gross kaross bros harrows pharos grows kouros heroes morose praos giros porous borrows karoos brass narrows biros brosy serous brios rosy cirrose euros arrows porose marrows guiros prose priss crosse ceros churros cheeros charros truss trows trios trass torose tiros hydrous duros drossy dress saros broos frass prosy barrios parous proso crass zeroes farrows burros gyrose crows serows caress brose heros karroos seeress sorrows grass zeros frows aurous morass pyros arose furrows morros brows harass heiress cerous vireos eros briss pros gyros barrows prows serosa ferrous curios rose morrows faros press cress pareos burrows peeress rerose froes erose cuirass vrows hydros rows toros taros roes torous tress cirrous trois troys duress tyros cheerios proas chiros yarrows