If you're into building your own Providers, the "ASP.NET 2.0 Provider Toolkit" includes full source-code and information about building your own Providers for Membership, Role Management, Health Monitoring and Personalization in ASP.NET v2.0.
The Toolkit currently include source-code for the Beta1 Access provider. Later this year it will be updated with Provider support for SQL Server, SQL Express and AD/AZMan.
Download ASP.NET Provider Toolkit
Read more on the Blog of ScottGu