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.
zinnias zins siennas zeins zines sunnas zanies xenias sennas sunnahs sonnies sins cines zones sunns zincy zanza cions snaws sines sinus sains sinhs zoons seines sinews sanies saunas scenas scions sanious sinuous
zinnias annas minnies nannies gunnies goannas manias johnnies jinnis cannas sunnahs xenias donnas siennas taenias rennase tennies pinnas tunnies pennies shannies nonas hinnies bennies jennies hyponoias nanas ninnies bennis bunnies mannas fannies funnies ennuis hennas sunnas duennas sonnies tenias sennas tennis pinnies whinnies pennis shinnies