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.
roil reoil roily riel rial roll rile role rail rill rouille riley rille rouleau rale real reel rely rule ruly rally rawly relay wryly
boil foil coil moil noil oil reoil roil soil toil