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.
seneca senega sneak sneck scenic sneaky snag sync snuck sonic sanga snick snaky snack xenic seeing snaggy
seneca neck fanega fennec finca vinca wryneck senega sneak sneck tunica
sene sen esne syne sone sinewy sinew sine sewn sienna senna seine seen scene scena sane usnea