Accelerometer is now very famous because it exits in most of the smartphones like iPhone, Android and Palm Pre. Recently, I got a RC mini-helicopter with built-in gyroscope to detect the rotational movement, it makes me interested in the differences between the two sensors. After some Googling, I found a good video tutorial that compare the two sensors. The InvenSense, whom made the Wii MotionPlus, using Gyroscopes and Accelerometers to capture precise human hand movement. The comparison video goes here:
My cheap RC mini-helicopter:
The single-axis gyroscope inside the helicopter:
It is used to detect if the helicopter rotates left or right unintentionally while the main blade is rotating. The MCU inside the helicopter would try to control another motor to rotate another blade to counter the rotation if necessary based on the gyroscope reading.
Here is my video showing the balancing control of the helicopter:
Furthermore, there are some articles worth to read: