I’ve written in the past about how easy it is to steal a laptop. While common sense still remains the best defense, a tool which may appeal to those which are extra cautious is Laptop Alarm.

This free to try program’s functionality is very simple, from their web site:

Laptop Alarm emits a loud alarm when:

The power cable is unplugged
The mouse is removed
The laptop is shut down

One of their testimonials states:

Laptop alarm is just great when I’m sitting at Starbucks or an airport and you got to go to the bathroom. I really can’t live without it

Now keep in mind here this tool is no substitute for common sense, rather a compliment to it. Someone could still forcefully shut off your machine very quickly by either holding down the power button for ~5 seconds or by removing the battery.