KVM (keyboard, video or visual display unit, mouse) are very useful tool if someone want use multiple casing (cpu!) and one display, mouse, kb.
http://en.wikipedia.org/wiki/KVM_switch
http://en.wikipedia.org/wiki/KVM_switch
Many little things we learn everyday which might be helpful to others - specially in r-e-s-e-a-r-c-h. Just like to share.