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.
yaups yaps yups yawps yeps yips yuppies yipes yippies
whaups jaups yaups ups pupus knaps napas laps heaps saps papas capes upas naps gawps pupas chaps leaps raps maps soups waps daps yawps dupes yaps chapeaus sups coupes caps gapes quips coups cheaps tapas tapis jupes taupes capos haps loups wraps supes whaps soaps gaps lapse lapis rapes kapas loupes baps lupus pups neaps paps napes chapes tapes roups whups reaps japes pause apps tups taps apes apse shapes cups dups apos diapause cheapos zaps yups
yaup yap yup yawp yuppie yuppy