The last screencast (I think) from me about Authentication in SharePoint. You can find it over at Channel9 here:

http://channel9.msdn.com/posts/BomBom/Building-your-own-MemberShipProvider-in-ASPNET-20-and-use-it-in-SharePoint/

In this screencast I build a MemberShipProvider that is checking the users against an XML file instead of a SQL database ("using virtually no code at all").
I build it in ASP.NET 2.0, use it that site and then show you how easy it is to move it over to SharePoint.

This webcast builds on the previous ones, 
Forms Authentication with SharePoint (in English) and Authentication Provider .Net 2.0 Out Of The Box.

Yeah, I know the code speaks for itself, but this time I made it in English anyway.

Enjoy!