BookControl is a fully templatable silverlight 4 control that looks and acts like a hard paged book. The Covers and pages are templatable. The control itself and the navigation buttons are templated too. The control is available for free download without the souce.
Very nice feature is the Transparent pages support
HOW TO USE
When control is empty it has only two covers which will be filled with the first two and last two elements declared in the body of xaml. The Content property for the control is PageElements. The elements used to fill the pages are UIElement-s. Find the supporting URL where you can get a sample xaml code used to create the DEMO.