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.
checkup chickpea shakeup
checkup backup fuckup cockup kickup lockup mockup pickup recoup teacup wickiup cup
check cheek cheeky chick chickee chock chuck chucky chechako cheechako