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.
ripe rip rape rope ropey rupee rappee rep rap reap repo repp ropy roup wrap repay roupy
lipe pipe ripe sipe wipe yipe pe