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.
rougher rover roofer reoffer refry refer river rifer raver refire reiver riever reefer reaver revery revere reefier referee reifier reverie riviera riviere
cougher laugher rougher tougher higher nigher sigher weigher