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.
backup beaucoup becap
backup mockup lockup checkup cockup fuckup pickup kickup cup scaup lookup wikiup coup teacup beaucoup takeup makeup recoup hookup wickiup scup shakeup
back bake beak beaky beck bock buck bucko abaca aback abaka babka