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.
coypous coypus copious cops capos coops copes copse coups coupes copays copies cowpies cowpeas caps cups kops capes goops capias cuppas koppas quipus coppice koppies quippus
coypous hypos pious copious coypus lupous pappous spouse typos pus