Handheld Distance Calculator

  This is a handheld device that is used to measure the distance from a fixed point of origin.
  A known point on the earth's surface is taken as the device's reference point (acceleration, velocity and displacement zero). As the device is moved from this point, it should measure its acceleration and time. The distance travelled can be calculated using equations of motion in physics. Thus at any point in time, the device knows its position relative to the reference point.
  This device can be used as an alternative to GPS in cars etc. Also u can measure how much distance u have covered while sitting in a plane, train, bus etc. Also it could be used to trace a path which it is moved through. The difference between this and a car odometer is that it does not require a moving wheel to touch the surface over which it moves.