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.
decoy deco decay deck dicky dekko dykey dikey ducky doggy dickey doc dog dago deke dick dike dock duck duke dyke taco
decoy coy cowy gecko coky pecky decay deco