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.
priapi preppie perp prep prop preop hyperopia prepay preppy pyrope hyperope
para parae pariah peri prao prau pray proa puri apiary spray