By way of Harry Pierson's DevHawk blog:
patterns & practices has published a new App Block: Authorization and Profile.
This block is a reusable code component that builds on the capabilities of the Microsoft .NET Framework to help you perform authorization and access profile information.
You can read it online or download it.
If you have worked with Shadowfax, some of this code should already be familiar (under the Security folder). It's great to see it is now available separately.