Put your monitor to power save mode, with Sleeper
If you are a power-save mode fan, you will appreciate a small utility that will let you send your monitor to sleep easily. Sleeper lets you define whatever hot-key you prefer to run it and activate the power-save mode of your monitor. Exiting power save mode is as simple as you already know: just press whatever key of your Keyboard, or move your mouse.
You may like also to check this post if your PC wakes up by itself a few minutes after you put it to sleep — or download right now Super Sleep instead of Sleeper, an equally small and free, but more powerful program, that makes sure your monitor remains in power save mode until you decide to wake it up. Sleeper works on Windows 32 and 64.