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.
sprawl sprawly sporal spiral spirally spryly superreal superalloy sparely spirula sporule spirilla spirulae superlay superlie
sprawl parral prowl caporal papyral puparial spiral sporal sprawly superreal chaparral
spray spirea supra spurrey spur spry sprue spree spore spiry spire spar spiraea spear sparry sparrow spare spurry osprey