The accelerometer is also the base of any inertial navigation system such as some aircraft autopilots, or ship nav systems. A set of accelerometers continually measures acceleration in all three dimensions; the second integral (thanks baffo!) of these values will give you the distance traveled in each direction from the starting point (well, not that simply, but using that method).

Many accelerometers utilize gyros of some sort, from mechanical gyroscopes to ring laser gyros.