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.
sparely spryly sprawly spirally superreal spiral sporal sprawl superalloy sporule spirulae superlay superlie spirula
sparely parlay parley parrel pearly purely apparel
spare spar sparrow sparry spear spire spirea spore spree sprue osprey