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