Another of Trimoon's methods can be found described in this very popular thead: http://www.retouchpro.com/forums/showthread.php?s=&threadid=4110

Member Alex recently created an action set to make the layer building process a little easier, too. Check out his contributions starting here: http://www.retouchpro.com/forums/showthread.php?s=&postid=56190#post56190