I think a while back researchers wanted to create a network of Mac laptops to detect earthquakes. I remember reading about it. Not sure what became of it though.
Edit: Quake Catcher Network. And it looks like it started in 2008 and used Macbook pros. Still cool though and probably similar hardware.
That's pretty neat. I saw on the site that there was software to use the sensor as a general interface device. Would be pretty funny to see some sort of Accelerometer-based game running on an ibook.
I don't see it on the list you posted, but my cousin way back around 2008 had an application that showed particles/balls that would bounce around the screen and move based on how the laptop was tilted. Anyone know what that one was called?