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.
gawps gaps gapes caps capes capos goops kapas capias kappas cowpeas cowpies guppies kewpies cops cups keps kips kops
gawps yawps kapas heaps jaups capos rapes saps reaps zaps papas paps naps tapis napas gaps waps maps whaups lapis chapes lapse cheapos gapes shapes caps yaups capes tapas apse taps baps apps raps soaps wraps daps papaws pawpaws neaps tapes napes haps whaps knaps wops laps chaps leaps cheaps apes yaps apos paws japes
gawp gap gape gappy gapy agapae agapai agape