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.
clog colog cloggy clag cloak glogg collogue clock cloque colugo cloaca calico cloacae glug calk colloquy gleg colloquia colleague caulk clack cleek click cluck colic gulag
log blog flog clog colog sawlog slog dialog duolog