Last night a lot of people were amused by the trick with enabling IntelliSense in Web.config. So, I decided to post it here. All you have to do is to remove xml namespace attribute (xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0") from <configuration> element of your Web.config. Yes, it's that simple

Don't forget that you'll have to do this procedure each time after you launch ASP.NET Administration Web Site because it consistently puts namespace back in.

Enjoy!

PS You can read about enabling IntelliSence in .skin files here.