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