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.
drops dropsy droops hydrops dorps drips hydropsy drupes tropes drapes troops troupes towropes traps trips tarps turps trapes tripes tripos traipse trappose trappous
crops hydrops drops props chirps hydropsy tropes roups towropes groups herpes droops perps rips craps trips sharps preps croups grips liriopes bewraps preops pyropes sirups dorps dropsy urps gorps wraps troops raps turps gropes traps rewraps ropes carps carpus corps corpse chirrups tarps warps corpus harps larrups burps syrups drips reps hyperopes fraps sherpas
drop dorp drape drapey drip drippy droop droopy drupe trop trope