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.
sphere sphery sypher cipher cypher severe sigher safer saver sever siver soever suaver suffer zephyr savvier
sphere referee weigher sypher revere higher cougher gopher laugher nigher fere reverie faerie riviere rougher cipher cypher severe sigher sphery tougher chevre