Jon Flanders has written an article about how to imlement a Page Controller, otherwise known as UI Page Flow. This allows you to configure the flow of web pages viewed by a user using Windows Workflow Foundation. Previously the transitions between web pages would be done in code with logic on each web page.
For some reason the MSDN Blogs site is very slow today. While I have it's attention I want to link to Mike Taulty's presentation that he gave recently. Mike gave an overview of WF and he has also published a whole lot of demos that he did at the session.