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.
spirea spiraea spire spier spree spore spare supra spear speir spray sprue spiry sapphire seepier sappier soupier soapier spurrey soppier spar spry spur sopor speer spoor super sapor sapour sapper sipper soaper sparry spurry supper sparrow zappier zippier
spirea perea pereia capoeira sapphire spiraea spire