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.
codon coden codein cotton godown codeina codeine cottony cotan guidon
codon don wooden redone rattoon radon lowdown guidon dona done down toon adown photon vodoun vodun voudon voudoun hoedown iodin coden godown loden odeon ratoon redon udon showdown
cod coda code codeia coed cooed cooeed coot cootie coude cocotte cooked cookout scoot