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.
protein protean proton preteen pertain pardon partan parton pardine predawn puritan pyridine peritonea pieridine preattune hypertonia
protein rotten carotene carotin carrotin cortin protean serotine serotiny torten chorten shorten