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.
populace papules peoples popples papulose popeless populous peepuls pipeless peplus pipals pupils
populace palace place plaice noplace replace showplace
papula papulae papule people popple