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.
spool spoil spell splay spill spile spiel speil spall spale spail sepal speel supple supply sappily soapily zeppole zeppoli
spool pool pol pole poll polo poly cupola maypole repoll spoil zeppole zeppoli dipole duopoly