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.
collogue colleague colog colloquy cloque colloquia clog claque calque clique colugo cloggy cliquey cloacae clag cleek cloak clock cluck colic glogg cliquy cloaca
collogue dialogue duologue cloque plague log
callow collie colly coolly col