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.
pappi pappy pap papa papaw puppy peppy poppy pawpaw pep pop pip pup peep pepo pipe pipy poop pope pupa pupu
pappi app yippie cheapie buppie happy hippie gappy kappa koppie nappa nappe nappie nappy pappy sappy zappy chappie chippie yuppie
pappi pappy pap app pawpaw sappy papaw puppy papa poppa peppy kappa nappy nappa gappy happy poppy nappie rappee nappe zappy