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.
troop trop droop trope droopy troupe drop tarp towrope trap trip tripe trippy dorp drip
droop troop trop rope ropy roup crop croup grope hyperope group preop prop pyrope droopy drop towrope trope
taro tiro toro trio trow troy tyro rooter rootier rotor strow stroy tooter