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.
trooped drooped trouped torpedo trapped tripped dropped draped torpid tripod trepid dripped tripody trippet dropt trapt dropout
trooped drooped roped rouped cropped groped grouped propped dropped trouped
troop trop droop droopy trope troupe strop stroppy