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.
readiness reediness redness ruddiness rowdiness retines ratines retains radians redenies rudeness retinues radiance redons redans ruttiness radons reattains rootiness rottenness retunes reddens retinas retenes ratanies routines radiancy rutins ratans ratoons rattans rattens rattons ratteens rattoons routinize
beadiness giddiness woodiness muddiness gaudiness weediness bawdiness neediness tidiness shoddiness reediness moodiness shadiness dowdiness ruddiness rowdiness seediness readiness headiness dines pettiness madness nudeness pottiness fitness rootiness nattiness ruttiness codeines redness nuttiness doughtiness lewdness badness haughtiness dottiness deadness iodines fattiness knottiness wideness goutiness jettiness cattiness voidness matiness battiness sadness dienes loudness witness meatiness goodness rudeness tattiness bittiness wittiness chattiness oddness sootiness dins
radian retain gradin gradine uredinia