We have reviewed a freeware tool yesterday to turn of laptop monitor when not in use. Here is another free tool called Dark, to turn off your laptop monitor. Dark is an open source .net application to turn off your laptop/computer monitor by double clicking a Notify Icon. The application sits in the system tray and you can wake up the screen by any mouse or key movement. The application is developed by Shoban who has also developed the famous TweetMyPC and Gtalk Autoreply applications.
You can also start the application with Windows startup, this can be done by right clicking the tool in the system tray.
This is the simplest of tools to turn off laptop monitor and also very easy to use.