Shake to wake for Nokia N900. Idea from http://maemo.org/community/brainstorm/view/shake_to_wake/

Python script uses acceleration sensors to detect shake, then dbus command to open up the screen. It wont open the screen if proximity sensor says it’s closed. This is to prevent unwanted openings. For example if you have your N900 in your pocket 

You can watch the demo below (i can't embed it, i have no access to youtube, damn google...): http://www.youtube.com/watch?v=RYmJ95rSj-A

Python script is available here

To install, copy script to your phone, /home/user/shake/shake.py and start it by running command :