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.
heartily hardily hardly hartal horridly hurtle hierodule hurriedly
heartily artily dirtily tartily curtail wordily portly torridly courtly fruitily luridly quartile grittily curtly prettily fertile pertly hardily peartly tardily aridly partly tartly horridly tortile ruttily shortly
heart hearty hart heard hereto