Rotation Measurement

Hi Folks,

I am a sensor newbie. I would like to measure rotations per minute (RPM) of a spinning toy globe. How can RPM be measured with mems gyros or accelerometers or their fusion ? How do I determine the orientation of axis of rotation (our globe is not regular globe that is mounted on a fixed stand - rather the stand can move and tilt in any direction) ?

Can RPM be determined by reading gyro values in x, y,z directions and finding resultant vector ? Would magnitude of resultant vector give RPM and direction ?

Thanks in advance for the help, and knowledge.