How to disable an external display but still have it hooked up?

[Qwerty11]

I have three displays on my Mac, but sometimes I want to use one for another computer. Trouble is the Mac still thinks it is using that display, thus it will launch apps and stuff on that display and I cannot see them. Besides unplugging the cable to the display from the Mac, do I have any other options?

 

[Rad]

SwitchResX

Check out SwitchResX. I use it for that exact reason.

http://www.madrau.com