Been catching up on the ole blogs when I ran across a post from Scott Guthrie about a new ASP .Net 2.0 feature with a file called App_Offline.htm. 

"One of the new features I talked about was the "App_Offline.htm" feature in ASP.NET 2.0, which provides a super convenient way to bring down an ASP.NET application while you make changes to it (for example: updating a lot of content or making big changes to the site where you want to ensure that no users are accessing the application until all changes are done)."

From: Scott Guthrie , App_Offline.htm and working around the "IE Friendly Errors" feature

I must admit thats pretty awesome and very welcomed.