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.
hippo hippy hip hippie happy hoppy hoopoe hoopoo huppah hap hep hop hup heap hoop hope
hippo hippy quippu quippy lippy nippy pepo zippy dippy tippy whippy chippy