I am starting to learn Mobile Phone Application Development. Suddenly this idea clicked in. The app starts with the Phone in rest on your living room table. Now, the phone is picked up from the living room and transported to the dining room. Could the app be able to tell this? Here is how I think it. If I constantly monitor the acceleration in all three axis, I could be able to tell the instanteneus velocity about those axixes. Then time integral should provide me the displacement? Is there flaw somewhere? Can the mobile phone accelerometer be fast and accurate enough?