Nokia has been kind enough for lending me an awesome N900. This will allow me to test KOffice on the phone. Document loading, parsing and scrolling speed could do with improvements.
Apart from using the N900 for serious things, I've also done a bit of playing with it. Qt has a famous OpenGL demo that shows the Qt logo in a QGLWidget. Instead of controlling the rotation of the object with the scrollbars, the adapted version uses the accelerometers in the device to move the logo.
This was a simple adaptation: reading the accelerometers is simple:
Nokia-N900-41-10:~# cat /sys/class/i2c-adapter/i2c-3/3-001d/coord 36 -18 -1134
Here is a screenshot of five running instances in the application overview. The five logos all move if you move the phone.
Perhaps a Qt on Maemo guru can adapt this program to be a desktop widget with a transparent background.