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.
cynic scenic sync snick sonic xenic
cynic genic hyenic tunica tonic xenic sonic scenic runic pianic hypnic aeonic hyphenic phonic vinic ionic nick conic pionic hyaenic tunic tannic sync snick bionic panic hygienic muonic manioc manic maniac quinic kaonic yonic