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.
preop prep prop prepay preppy pyrope perp preppie hyperope hyperopia priapi
preop rep trop towrope droop prop reap hyperope repo repp rope ropy roup crepe arepa creep crepy crop croup grope group kreep prep pyrope drop troop trope
pro prao repour pyre puree pure prow proa prey pree pore pare pereia perea pere pareu pareo pyro spree