GPS & Communications
I was on a project for something similar - for Olympic hopeful runners in training. It needed GPS, voice communications, *and* vitals monitoring (heartbeat, blood pressure, res) - in real time.
Sensors, wires, mic, headphone and box (made from Radio Shack parts & some off-the-shelf kit) weighed in a less than 1kg without the batteries (3 AA Lithium).
It could withstand sweat, heat and movement from running for miles (and hours), and was regularly monitored from outside the track (about 1 mile through concrete, steel, etc) as it was easier to keep the kit in a van in the parking lot then get through security into the stadium.
Total price???? $800.00 USD (in 2002 dollars). Such a system could easily be wired into the normal MOLE base, and take up the room of an ammo pouch, maintaining the waterproofing, etc.
However, I have done work for the military before (service-side) and know that most of the cost is in meeting the milspecs for environment, etc. I would expect that to triple the price (ie. cost of the actual testing and certs done during development, the resultant packaging and manufacturing costs (and margin) would be end price), bringing these in at under $2500.00 USD each. A bargain compared to the prices I have been seeing bandied about here and through other news outlets and my mil buds.
I would be happy to take the contract for continued development and manufacturing, with proper terms for specs, usage and warranties... Taking a bullet in the electronics "brick" would not be covered, however... :)