Most of the Laptop or Notebooks does not have an option to manually turn off the LCD screen. Turning off the LCD screen will save power and it make sense to turn off monitor in case you are downloading files overnight. Windows has an option to turn off monitor when kept unused for some time, but this feature is not always good. Turn Off LCD is a simple freeware application which will allow you to turn off your notebook screen saving some electricity.
All you need is to download and run the file and no installation is required. The file is only 89kb in size. You can add a shortcut to this application in desktop or quick launch.
According to the owner of the application, its coded in C# using Microsoft Visual Studio 2008. Its basically a simple console based application that makes use of a dynamic link library (User32.dll) file from Windows using System.Runtime.InteropServices namespace and then calls the required function.
This application works in Windows Vista as well.