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.
yellowy yellow yell yill yowl
billowy willowy pillowy yellowy sallowy tallowy sallow yellow callow mallow allow lowly tallow pillow hollow follow hallow wallow fallow blowy billow alloy bellow willow fellow shallow mellow low