From the Microsoft Patterns and Practices Team comes the Web Client Software Client Factory June 2007 Release.
WCSF makes use of Guidance Automation, Application Bocks and Libraries.
It makes developing a composite Web Application much easier and automates several (otherwise laborious) processes whilst also offering advice and guidance on various topics.
I have found it makes implementing the Model View Presenter pattern very quick and easy.
Its also worth a look if you want to get into developing Page Flows using Windows Workflow Foundation.
You can read more and download it from the official web site.
Official Web Site
Getting Started with the Web Client Software Factory