Trust the Japanese to come up with this. By analyzing how smartphones with built-in accelerometers relate to everyday actions, i.e. walking or running, KDDI Laboratories has apparently found a way to help supervisors do their jobs better.
The motion patterns from the cellular are sent to a back-end analytical server, which then matches and determines the type of actions associated with the phone. Of course, the accuracy of such an implementation will get better over time as more data is collected, but it's really all moot if you don't carry the handset with you when you're catching power naps in the bathroom.