Matt Winkler gave a session this week at TechEd where he described how to use Windows Workflow Foundation (WF) to control the page flow of a client-facing application. This has certainly been a popular request since the early days of ASP.NET (giving rise to such MVC frameworks as Maverick.NET.) A preview of this technology was given at TechEd 2006, but didn't make it into the current release bits.
The good news is that the Page Flow sample is now available with full source code. It includes a new PageFlow project template, a new Navigator workflow type, and new controls (InteractionActivity and InteractionGroupActivity) for Visual Studio. This sample can be used with multiple UI technologies (e.g. ASP.NET, WPF, etc.)
Read Matt's Post for full details and a sample use case.