Japanese company KDDI has developed technology for cell phones that uses something called accelerometers to track precise movements, then beams all that info back to a central location. And we're not throwing the word "precise" around willy-nilly here. These guys can tell if whoever wearing the phone is sweeping versus scrubbing, walking versus running, doing number two in the bathroom versus doing number two in the secretary's filing cabinet. It's that sophisticated.
Link - via mentalfloss
From the Upcoming ueue, submitted by nmiller.