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.
rattens ratteens rattans rattons rattoons ratans reattains ratoons ratines retenes rottenness ratanies ruttiness rutins redons redans radons retines reddens radians retains redness rhytons retunes retinues routines rudeness redenies readiness reediness rootiness retinas
fattens rattens pattens kittens lattens battens mittens tens buttons stenos retenes ratteens lattins rattans rattons ketenes butenes steins sateens catenas wheatens luteins tautens quietens potteens jettons cottons latens poteens heightens teens neatens muttons mattins lateens tense patens whitens
ratteen ratten rattan ratton rattoon reattain rotten