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.
guck guaco quick quack quacky guaiac cuckoo quickie gowk coky kick cook kagu gook coke caky gawk cake cuke keck cock cakey cocky cooky gawky gooky kicky quake quaky
buck fuck huck guck luck muck puck ruck suck duck tuck chuck shuck yuck