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.
propel propyl propyla propylaea purple purply prepill preapply preppily
propel rappel repeal repel ripely carpel graupel propyl
prop perp preop prep prepay preppie preppy pyrope