I've got a pet and it is a bright and intelligent creature. In the past it caused some buffer overflows because walking over the keyboard was a direct way to get my attention but today my Windows session was locked and it decided that it would walk over my keyboard again.
It managed to hit the right shift key for more then 8 seconds and then enter. This resulted in my keyboard making noises ... a sound for every keystroke. Driving you crazy when you have a long passphrase instead of an 8 character password.
To undo it I had to hit the right shift key for 8 seconds again and hit enter. A nice little practical joke but I am sure if I would pull this off in an office during lunch hour some people will go crazy.