Is there a simple app, key combo, or a way I can use AppleScript, to turn off my monitor manually (resume on mouse move)? I need something like this for the automatic input switcher on my monitor to work.
its not a keyboard shortcut but its a screen corner go into system preferences and click on expose and spaces and there you can pick a corner to put the display to sleep
You can set up a hot corner to sleep the display in System Preferences > Mission Control > Hot Corners (10.7) or System Preferences > Exposé & Spaces > Exposé > Active Screen Corners (10.6).