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.
spells speels spalls speils spiels spills spoils sepals spails spales spiles splays spools sapless supples sepalous soapless soupless supplies splice
spells apollos tupelos spiels speils spalls repels rappels lapillus lapels cupels appels appeals paellas pulls palls polls pills peles peels peals repeals repolls speels appalls spills chapels
spell spale spall speel speil spiel spile spill splay