Distributed Biotech Sensing
Here's the idea:
One million insects are equipped with a color photocell and a nano-watt laser rangefinder, and a radio transmitter. They are allowed to fly & scurry around on their own. Each second the photocell records the color of its single-pixel and the distance to the nearest object. A computer records its position and vector. This information (7 elements) is transmitted to a central computer that constructs a 3D image of the landscape.
The question is: how long would it take to obtain a complete image of the landscape down to millimeter resolution?