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.
purpose propose porpoise perps preps props preops prepays pyropes preppies hyperopes hyperopias prepuce priapus
purpose reoppose repos repose corpse porpoise propose trappose tripos charpoys