[mechanicalbrain]

The accelerometer would measure the g-force in a direction. You can run this through a simple equation and you would know the distance you have traveled in a direction (im working on this because it's more accurate than encoders). Im not that great of a programmer but you could save this and your robot would be able to travel around and make maps of a room. You actually see this type of thing on rockets but it has some cool aplications in robotics.