Knock-based commands for your Linux laptop
You probably know that the T42 comes with active protection for the hard drive. Well using that technology it's possible to simply "tap" your computer and have it respond accordingly. Example, tap your laptop and have the track change or double tap somewhere to lock the screen. I havent tried setting up all of this but when I do I'll post-- dont worry!
For the first time, you can hit your computer and get a meaningful response! Using Linux® and the Hard Drive Active Protection System (HDAPS) kernel drivers, you can access the embedded accelerometers on Lenovo (formerly IBM®) ThinkPads, then process the accelerometer data to read specific sequences of "knocking" events -- literally rapping on the laptop case with your knuckles -- and run commands based on those knocks. Double tap to lock the screen, and knock in your secret code to unlock. Tap the display lid once to move your mp3 player to the next track. The possibilities are endless.