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.
dark darky darkey darkie dirk dork drek dreck tarok drouk dorky daric drake drecky derrick trek drag drug dreg turk duroc taroc track traik trick trike troak trock troke truck
ark bark hark cark quark lark mark nark park sark dark wark chark shark