[ekapalka]

Believe it or not, there is actually a "typical" way to do this. It's called field-centric control, and is in fact so popular that it is included in the with the developing software (C++, Java and LabView, I think...) as an alternative to the more common robot-centric control. The only sensor needed is a gyro. Magnetometers haven't proven particularly successful for teams to use in competitions due to their high sensitivity (high enough to detect the earth's magnetic field -> high enough to detect the electronics on other teams robots). I'm not entirely certain how you would incorporate the accelerometer if you were going to use one... What language are you using?