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.
spell spall speil spiel spill speel splay spool spoil spale spile spail sepal supple supply sappily soapily
spell appall chapel spill pall speel ripely repel repeal rappel lapel cupel appel appeal pull paella poll pill pele peel peal repoll spall speil spiel tupelo shapely