The technology to be demonstrated is an activity recognition system that runs on a standard consumer mobile phone (HTC Dream). The phone is on a belt clip attached to the waist of an individual, and is able to discern whether the person is walking, running, biking, walking up or down stairs, or standing still. Additionally, the device can be trained to detect a user from their walking gait. We will allow a number of users to provide training data, and then we will demonstrate the ability of the device to detect which person is carrying it from their gait.