Sleeper

If you are a power-save mode fan, you will appreciate this small utility, that will let you send your monitor to sleep with a keyboard shortcut. Of course, you can tell Windows to activate power-save mode after a time of inactivity, but a keyboard shortcut is the most flexible solution, letting you rely on your decision, instead of some automatic adjustment which sometimes 'strikes' exactly a few seconds before you need your monitor again. There is also the obvious On-Off button of the monitor itself, minimizing even more power consumption and monitor decay, but next to that, a keyboard shortcut to enter power save mode is the best way.