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.
safety softy suavity sift soft saved savate soffit softie soviet saphead savvied seafood scyphate
safety fet wifty tufty taffeta softy nifty naivety lofty lefty hefty haffet fifty effete buffet fete feta feet feat defeat tuffet whiffet shifty