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.
cuckoo cock coco cook cuke guck kook quick quack cooky cocoa cocky cacao kooky coocoo cookey cookie kookie quacky quickie cog
cuckoo coo boocoo bookoo bucko gecko jocko coco coocoo cook kook sicko socko wacko whacko shacko
cuckoo buck yuck chucky tuck duckie sucky ruck bucko fuck huck cock cocky cuke guck luck luckie lucky muck mucky puck pucka suck duck ducky chuck chukka yucky