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.
speisses speises species sepses spices spouses specious supposes sepsis spaces spazzes spacious
pisses speisses pussies speises repousses repossess repasses lapises capiases bypasses passes pusses poussies possess posses poises peises tapises
speise speiss sipes spaes specie spews spies spues supes aspis