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.
greater grater greeter grader krater crater garter creator gritter grouter greedier grittier groutier creature garroter garotter grottier carter curter gridder grodier courter quarter guarder curator critter courtier criteria quartier cowriter carrotier carder corder cruder crittur crowder curdier
greater treater ureter tarter ferreter treader darter perter narrater krater ratter reader barrater barter prater frater irater fretter carter crater creator garter grater greeter quarter pearter rater charter
great grat create grate greet groat egret