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.
quitter quieter quittor quoter cutter gutter guttery guttier cuter kiter goiter guider quatre guitar couter cotter gaiter cautery cottier gaudier cattery goutier cattier cater gater coater cooter cottar cuatro goitre kidder coterie couture gaudery
bitter fitter knitter whitter quitter titter litter sitter hitter ritter jitter chitter nitery gutter pettier setter titer battery jittery petter pitier baiter bittier quittor cottier letter hotter cattery liter rioter guttier getter cattier fatter chattier mitier niter dotter shutter shatter chatter nettier whiter wetter waiter tottery toter tater suiter butter rattier rotter tattier otter puttier nittier knottier nattier vetter lotter buttery pottier fetter mattery reutter nutter littery battier gaiter kiter jotter lottery miter better nuttier cotter mutter quieter jettier netter pottery writer patter batter whitier latter potter gnattier biter hatter phatter ruttier loiter matter fattier knotter cutter citer natter ratter dieter putter tatter dottier tetter guttery totter utter watter whetter wittier chattery goiter shittier yatter