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.
spiel speel spail speil spell spile spill spoil sappily soapily sepal spale spall splay spool supple supply
spiel pill ropily repel peppily rappel peel pele loopily pile pial pili spill pily dopily speil uppile spail choppily sappily peal plie happily ripely repeal nippily pupil cupel huipil lapel appel appeal pail spile spell spoil speel tupelo soapily chapel roupily shapely
sepia sipe spae spew spue supe