The Microsoft Ajax CDN enables you to significantly improve the performance of ASP.NET Web Forms and ASP.NET MVC applications that use ASP.NET AJAX or jQuery.  The service is available for free, does not require any registration, and can be used for both commercial and non-commercial purposes.

ASP.NET 4.0 will make it especially easy for ASP.NET Web Forms developers to take advantage of the CDN. By setting one property of the ScriptManager control, you will be able to redirect all requests for the built-in ASP.NET JavaScript files to the CDN and improve the performance of your Web Forms applications.

Hope this helps,

Scott

P.S. In addition to blogging, I have been using Twitter more recently to-do quick posts and share links.  You can follow me on Twitter at: http://www.twitter.com/scottgu (@scottgu is my twitter name)