Privacy schmrivacy. Self surveillance, now that is an idea! Fitbit, a start up in San Francisco has built a small sensor that tracks your movement 24 hours a day so you can record steps taken, distanced traveled, calories burned, and even how long you sleep!
The device uploads your data wirelessly over the web so you can compare your "movement record" with those of your friends. Link - via Technology Review
Gawd, the boingboingers will probably have a cow when they see this!
Or Actihealth: http://www.actihealth.com/Network.aspx