There is a very busy guy in Berlin | Germany: zehjotkah, who makes lots of Nokia N900 related Videos. I must recommend his youtube channel.

With his permission i will post here a few vids from him to show you how to work with Nokia N900

Today the Sensitive Motion for N900:

 This Game uses the Accelerometer of N900 to play with. see for yourself :-)

Source: http://www.youtube.com/zehjotkah