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