There are a handful of applications for Mac laptops that do this, using the built-in accelerometer -- for example: http://www.foozoodesign.com/lockdown.html htt

There are a handful of applications for Mac laptops that do this, using the built-in accelerometer -- for example: http://www.foozoodesign.com/lockdown.html http://www.foozoodesign.com/lockdown.html