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.
copse cops copes coops coups coupes coypus copies copays caps cowpeas cups cowpies coypous coppice copious kops capes capos goops capias cuppas koppas koppies gaps keps kips
copse ops posse pose poise coups kops lipase appose lopes loups mops oops oppose apse opus opes poops pops popsy repose roups soaps soups suppose dopas topes topos whoops woops chops pappoose pase knops pappose fops hoops hopes hops coops copes bops cops goops lapse loops lops mopes papoose biopsy popes popsie reoppose ropes hyssops sops spouse depose dopes topis tops whops wops shops
cop coop copay cope copy coup coupe cowpea cowpie coypou coypu scop scope