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.
sly slay silly sully sally seely sol sal sel sallowy slew slaw seel sulu sole soli silo soul sale saul solo sail sill slue soil seal sola sell sall slow sloe syli selah selle solei sallow scilla