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.
buffi buff buffo buffy bouffe baff biff boff baffy biffy boffo beef
buffi cuff chuff tuff duff ruff puffy pouffy pouff buff buffo buffy huff huffy bouffe kufi guff quaff quiff luff luffa maffia muff pouffe puff raffia ruffe taffia waffie chuffy