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.
lockup lookup
backup mockup lockup checkup cockup fuckup pickup kickup cup scaup lookup wikiup coup teacup beaucoup takeup makeup recoup hookup wickiup scup shakeup
lock luck flocky lackey lick loca loco look lack lucky luckie bloc block blocky bloke floc flock clock