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.
lack lac lackey lock lake laic luck lakh laky leak lick leaky lucky luckie lag lek leek leke leku like loca loco look
back hack jack quack lack mack knack pack rack wrack sack tack wack whack shack yack