When there is accelerometer coming out (http://news.jeelabs.org/2010/02/14/new-gravity-plug/), maybe compass plug too?
Jeenode is ideal for simple robotics (think about controlling roomba for example). Accelerometer is nice addition for that but getting orientation would be even better. 2-axis magnetometers are not really expensive (but soldering those is tricky part, same with accelerometers/pressure plugs etc.).