Be sure to tune into the Travel Channel on April 7th at 9pm, and you'll see Goober (Actor George Lindsey) stop by the real Mayberry--Mount Airy, NC. Host John Ritter stops by the real lake used in the opening credits located in L.A.
Full-info on this wonderilf special:
http://www.sitcomsonline.com/boards/showthread.php?s=&threadid=32439