A lot of energy is wasted when you keep the monitor on even when you are not using the computer. Most of us waste a lot of energy this way,so it better that you turn off monitor, especially laptop monitor which normally does not have an option to turn off. GreenMoni is a simple freeware tool which allows you to turn off your laptop monitor and also allows you to turn it on after the specified time interval.
The free tool is tested on 300+ monitors, so should work fine with almost all monitors. If you want to restart the monitor automatically, set the time and check the box. GreenMoni is a simple and useful utility. It also provides a direct interface to turn off monitor which can be pinned to Windows 7 taskbar for easy switching off.