One of the most common questions that I receive is how to display menu items based on login status. Because there truly are several answers with multiple options, it an become a little confusing, even to more advanced users. It really boils down to how to you want to construct your site and how do you want things to work?
I have provided different methods of doing this in the past, but that was often difficult for some users because you really needed to understand how to set up a child theme and do theme customizations appropriately. That is not easily within reach of all users.
So I have put together a plugin extension to make this process more automatic. Now you can handle everything through the WP Menus admin panel. It will automatically clone any menu areas of your theme, thus providing you with the ability to serve different menus for those menu areas based on whether a user is logged in or not.
Site members can download this and other extensions here.