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.
repot repeat repute rapt wrapt reaped repaid repped roupet
depot repot pot wept leapt pout boughpot bowpot capote copout poet kept lept sapote sept septa spout lepta spot teapot sapota wipeout
repo rep reap repay repp arepa crepe crepey crepy preop prep prepay preppie preppy