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.
screw screwy scree sucre score scare scarey secure scry scoriae scar scour sacra scary scaur sacker scoria scurry sicker soucar sowcar square squire sucker scarry cicoree suckier
crew screw decare sucre screwy core craw crow cure grew acre lucre care nacre ocrea regrew scare score scree fiacre secure daycare decree