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.
screen scorn squireen scrawny
careen green regreen screen squireen shagreen greeny checkrein
screw scree screwy sacra scar scare scarey scarry scary score scoria scoriae scry scurry sucre escrow