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.
wheatear whetter water waiter watery watter wetter whiter whitter wedder weeder weedier whitier watthour wader wider wadder widder
wheatear tear eatery dater fatter teary oater meatier later rater peatier retear beater watter matier tater batter tauter baiter tuatera attar water cater chatter shatter gaiter mater latter phatter seater gater eater pater neater matter ratter satara feater patter tatar datary tatter hater tuatara hatter waiter heater watery coater natter boater cheater yatter tar
wheat what whet sweat sweaty wat wet