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.
tropes troupes towropes tripes trapes troops trips turps traps tarps drops drapes tripos drupes dropsy droops traipse trapeze hydrops hydropsy trapezia trapezii trappose trappous dorps drips
ropes tropes gropes pyropes liriopes towropes hyperopes rupees preops crappies troops creepies crepes rappees croppies corps props hydropsy preppies frappes herpes harpies drapes drops rapes troupes trapes tripes crapes sarapes gripes grapes grippes gorps groupies serapes roups dorps ripes drupes groups crops droops dropsy hydrops cripes croups croupes sharpies
trope trop drop tarp trap trip tripe trippy troop troupe strop stroppy