Here's what all the fashionable soldiers will be wearing on battlefields soon, the Parvus ZYPAD WL 1000, a wrist-wearable wireless computer that the company rolled out at the Armed Forces Communication Electronics Association's TechNet 2006 International Conference. It uses a combination of WiFi, Bluetooth and GPS for location and communication, and can run either Linux or Windows CE. It has a 3.5" touchscreen LCD and has a battery life of eight hours.
Since this is a device that's intended for classified military deployment, its exact uses are rather murky, but one of its key capabilities is its accelerometer that shows if a soldier is still moving, or is motionless and injured. It can then be programmed to transmit a locator beacon for specified amount of time, allowing medics to pinpoint the location of the fallen soldier. From the looks of this picture, they're going to need to make that screen brighter if the WL 1000 is going to be useful in the desert, or in the fog of war.