Shortcut to disable keyboard/mouse in OSX On more than a few instances, I have accidentally disabled the internal keyboard and trackpad by a shortcut. 

The only button which works is the power-up key which I can use to wake up (if it's in sleep mode) and force quit by holding it. 

My question is, which keyboard shortcut (or keyboard and mouse click combination) does this effect and what can you do to undo it? To reenable keyboard/mouse...
This is a common problem for mac users, press the option key 5 times, and it will be fixed. 

Source:
     http://www.mackungfu.org/cat-proofing-a-macbook-keyboard