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.
speir spear speer super spiry spier spire soaper supper sipper sapper spirea spur seepier spar soapier soupier spry sappier spiraea soppier sapphire sapor spare sopor spray sprue spoor spore spree supra sapour sparry spurry zapper zipper sparrow spurrey zappier zippier
speir per mapper peri hyper keeper paper peer capper pear hopper coper popery gawper cooper copper pair gappier japer loopier quipper pappier sipper piper soapier heaper leper peppery roper pere mopery lopper caper gipper lippier lapper pier cupper nippier sappier toper deeper whippier whapper dippier tipper typier whopper dopier cheaper chipper weeper chopper shaper shopper yauper tapir soupier dupery zippier speer napery reappear spiry spier rapper wrapper ropier mopper diapir gaper raper supper peeper nappier zappier riper hooper sapper pipier ripper opera hepper loper coppery foppery viper popper spear apery beeper rapier looper kipper loppier coopery bopper hipper papery capoeira moper lipper pepper ropery hoper quippier leaper coappear appear happier aper copier cuppier gypper hippier hoppier repair mopier taper seepier napper peppier super spire nipper reaper dapper goopier dipper japery pauper zapper soaper soppier zipper knapper roupier duper tapper diaper whooper whipper doper tippier upper topper wiper cheeper chippier weepier choppier shipper yapper yawper
sepia sipe spae spew spue supe