If you are used to put your website under maintenance while you are updating it you will love this nice ASP.NET 2.0 feature.
You just need to create a file called app_offline.htm (with the static content that you want) in the root directory of you website and ASP.NET will unload the application domain and redirect all new incoming requests to that file.
Just rename or delete the app_offline.htm file and the website will be online again. Pretty simple, pretty cool :).