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.
greaten gratin grutten creatin gratine gratinee creatine garden cretin craton gradin keratin guardian cretonne carotene gardenia cowritten carton cortin croton carotin cartoon crouton curtain gradine guerdon quartan
greaten ratten retene hearten creatin marten preteen
great grat create grate greet groat egret