There have been a handful of interesting experiments involving use of the so-called Apple Motion Sensor or Sudden Motion Sensor that's built in to all recent PowerBooks and iBooks. Most of these projects have used a program called AMStracker to read from the sensor. However, the current version works only with the first powerbooks to come out with the sensor. It doesn't work with the iBooks and now the newest PowerBooks have yet a new way of handling the motion sensor. When I made my Carpenters Level Dashboard Widget, at first I used AMStracker. But it bothered me that I had to instruct people to download and install AMStracker. You see, it's proprietary and the creator, Ahmit Singh strictly forbids distribution of it. So, for the sake of making installation of my widget easier for the end user, I went looking for an open-source program that would do the same thing. I found it, it's called Motion, originally written by Chris Klein. Since it's open, you can distribute it along with your nifty motion- sensor-enabled-whatever-it-is. On top of that, I've adapted the original version so that it works on iBooks and have now adapted it again to support the newest PowerBooks. Ahmit still says he's trying to find the time to fix AMStracker for the iBooks (on top of that, he says that it's an OS thing but it's not, it's a hardware thing. Don't tell him. Let's let him think it's an OS thing).
Here's my beef. I'm still seeing stuff coming out for use with AMStracker. Why on Earth would anyone want to use it when there's an open alternative? It boggles my mind. So, if anyone is interested in playing around with Apple's motion sensor. Don't use AMStracker, use Motion. It's open and what's even more important is, it works. AMStracker works on one model of three. You can hardly call that functional. Also, if you know of anyone who is likely to do anything with Apple's motion sensor, share this info with them.
Motion can be downloaded (source-code, Makefile and compiled binary) here:
Support for the newest PowerBooks isn't in the compiled binary yet but the source-code contains comments showing how to implement it.