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.
cocoa coca coco coocoo caca cock cook cocky cooky caeca cookie cuckoo cookey cog cake caky coke coky gogo gook kook
cocoa oca boocoo hooka jocko coca coco coocoo loca loco poco soca socko
cocoa coco coo cookey chock poco loco cooky cookie coocoo cook cocky cock coca cooey cooee chook