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.
sinh sin sine sign sain sinew scion seine sinewy sunnah sienna syn sun sen son zin cine sewn sone sane syne snaw sunn soon cion sown zein snow zine sene sawn seen hyson senna snowy sonny sunna sunny sauna scena scene