Performing Back Navigation w/out adding a page to the Back Stack in WP7

In a previous post (here) I wrote about how you can catch the back button action on WP7.  In this post I will explain how you can use the NavigationService provider in WP7 to correctly navigate back to a calling page in order to remove a existing page from the back stack in order to prevent the user from going back to the page. Below is a pretty simple sample work flow.  You go from the home page