Today while reading few technical articles regarding OpenId authentication implementation in ASP.NET, I came across a nice article written by Mads Kristensen. Mads Kristensen article OpenID implementation in C# and ASP.NET explains how to easily authenticate web site users with OpenId service .
The entire source code of his demo application is available to download from here and it is ready to execute without any changes. Just open the downloaded code in Visual Studio and press F5 to see the application in action.
If you are planning to add authentication mechanism for a web application or trying to improve your existing web application authentication system, it is recommended to implement OpenId standards as major players like Google, Microsoft, Yahoo and Digg are backing OpenId.