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.
cruel cruelly gruel creel curule creole carrel carrell carl curl curly carle craal carol crawl coral curlew caroli greyly curial crawly corral cariole corolla criollo quarrel queerly carriole guerilla guerrilla
cruel gruel ariel reel areal ruly rule riel carrell rely jurel laurel barrel morula oriel purely cereal sorel sorrel surreal torula truly choreal merely real ferrel morel ferula ferule irreal carrel creel curule ferrule boreal barely loreal quarrel neurula parrel rarely saurel sorely surely direly trull ureal yarely
cru care core crew cure grue acre ecru ocrea ocreae scree screw screwy