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.
spoil spiel spile spill spool spail speil soapily sappily spall spale spell speel sepal splay supple supply zeppole zeppoli
spoil pol pili pile pial loopily nippily pupil pill sappily ropily spiel spill pily spile spool zeppoli dopily uppile spail pail speil peppily poll polo poly pool happily huipil pole maypole cupola repoll roupily soapily poilu zeppole dipole duopoly choppily