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.
trope troupe trop towrope tripe troop tarp drop trap trip drupe drape droop drapey droopy trippy dorp drip
grope trope hyperope towrope rope pyrope drupe serape ripe droop crape ropy croup tripe crepe trop roup troupe group troop rape gripe prop ropey preop grape drop drape sarape croupe crop cripe liriope sharpie
taro tiro toro trio trow troy tyro strow stroy