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.
papules papulose peepuls peoples popples pipeless popeless populace populous papillose peplos peplus pipals pupils
cupules pules papules puls couples pulse copulas gapless apples maples appulse nopales hipless nipples peepuls napless popples capless replies ripples soapless spales supples zeppoles dapples dipoles tipples topples wheeples applies lipless fipples pulis pulls huipiles plies plews pleas piles pales hopples peles hapless hoopless poles peoples maypoles reapplies repulse sapless soupless spiles supplies zipless diploes tipless topless uppiles shipless
papula papulae papule papal papally papilla papillae