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.
cropped crapped carped craped creped groped creeped gripped grouped carpet griped groupoid crept crypt crypto corrupt
propped cropped dropped wrapped trooped dripped trapped rapped repped ripped roped rouped bewrapped crapped gripped groped grouped prepped rewrapped drooped frapped tripped trouped
croppie crop crappie crappy croup croupe croupy