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.
sapour sapor spur sopor spore spoor spurry soaper sapper soupier soapier spurrey sappier spry spar sapphire sprue super spire speer speir spiry spier spare spree spear sipper sparry supper zapper seepier soppier sparrow zappier
pour vapour repour sapour pur puri spore vapory sopor sapor guipure pure vapor vapoury pore poor spoor purr spur