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.
casava cassava casefy
casava cassava piasava piassava save dissave
casa case cassia cause causey caws cays cacaos cacas ocas