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.
quaff quiff caff cuff gaff guff gaffe guffaw quaigh kaf cafe coff cuif kaif kufi
quaff aff caff cuff gaff gaffe guff luff huffy piaffe muff puff raff ruffe daffy taffy waff chaffy chuffy pouffe buffy huff naff buffi buff bouffe baffy baff quiff buffo luffa pouff pouffy puffy ruff daff duff tuff chaff chuff yaff
qua quai quay aqua aquae quack quacky quag quagga quaggy quake quaky squaw