Since a few of us have just won Raspberry Pis, and others already have them, I thought it would be cool to do a public brainstorming session for fun things you could do with it.
Some ideas I've had floating around for a while:
Sunrise Alarm Clock
Get a RGB LED Ribbon and connect it to your GPIO pins (unsure how right now). Then write a cron job, or some other app to run a script at a specified time that changes the lights to simulate a sunrise.
ToDo Lock Box
Get a box, and a motor that can be used to latch the box from the inside. Connect the RaspPi to the motor, and only let it open when your ToDo list is empty for the day (you can do this by querying the ToDo list's API).
Here is a guy that is using a RaspPi to control a bunch of different lights: http://blog.lastlog....ry_pi/#index4h1