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.
gaseous caseous gases gasses gausses caseose cases casus guises causes gooses casease quasses causeys guesses coses gazes casas cassis coseys cosies cusses gauzes gazoos kisses cassias cuisses gussies koussos
caseous gaseous nauseous osseous sous souse caseose masseuse paseos piceous poaceous reseaus rousseaus diseuse sos