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.
arider artier ardor ardour artery
rider broider torrider braider raider lowrider derider horrider arider joyrider herder carder heartier marauder corder portiere rewriter corridor ruddier forrader boarder grodier redder fruiter brooder redear crowder writer larder readier frettier partier dirtier shrewder shirtier wordier wartier troutier treader cruder tartier prouder nerdier murder bruiter prettier artier grader order groutier lardier purtier rowdier girder birder rudder hardier tardier parader border ruttier ruder cruddier cowriter rattier reedier rootier harder fruitier hoarder brattier courtier tireder broader ridder breeder quartier greedier gridder guarder reader grittier carrotier curdier rudery prodder grottier reorder prudery broidery broodier trader triter warder weirder chertier shredder yarder