There may be many times when you may want to leave your laptop on, but the default settings in Windows may take up to 20 minutes for the LCD screen to turn itself off, of course the time may vary depending on your settings.
I have faced a problem with the laptop light being on for almost 20 minutes after I head to bed, this definitely is quite a pain since the laptop is right next to the bed.
Turn Off LCD developed developed by Taimur Asad, is a real handy utility which will help you overcome this problem, by allowing you to quickly turn off the LCD screen with a single click.
The software is only 85Kbs in size and runs out of the box, without the need for any installation. Hats off to the developer for creating such a useful utility, will definitely help me sleep a little earlier without being distracted by the light coming from the LCD.