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.
cope coupe cop cowpea cowpie copy coup coop cape copay coypu coypou koppie cap cup kop capo gape goop cuppa cuppy goopy koppa
hope cope lope mope nope ope pope rope dope tope pe op