The inclusion of a gyroscope in the iPhone 4 made for some new possibilities. Previous models used the compass for features such as the AR shown above.
Because of the gyroscope, the iPhone 4 detects the phone's orientation and location much more precisely. Steve Jobs showed that off with a wooden block game similar to Jenga. In augmented reality Apps, this means better placement of the onscreen objects. Their movement is much smoother, and the objects almost seem to actually be in the scene. Notice how the iPhone 4 screen displays the objects, and they move across smoothly. Then watch the objects on the 3Gs screen. They seem to jump a bit as the camera pans around the room. We just hope people don't take to walking with their iPhone's right in front of their faces everywhere they go.
via Read Write Web