Quick implementation of an inclinometer with a 3 axis accelerometer on Arduino. It's a 3g model, which is a bit of overkill for this application.
I'll combine this with the electronic compass to compensate for inclination AND get an absolute heading measurement. I don't think I'll need the gyros.
I've since combined this with my Arduino-to-RC-Transmitter hack to control two servos remotely based on the inclination of the Arduino. Aim? Head motion tracking to pan a camera remotely.