In 2008 I worked with artist Ether Polak to prepare and film a journey to Nigeria.
In Nigeria we GPS-tracked two movements of milk from production to the market. First we joined a Peak milk truck that traveled from Ocean port of Lagos to the capital of Abuja, carrying condensed milk made from milk powder bought on the global market. The second part of the trip consisted of tracking the movement of Fulani herders who sell fresh milk from their cows on the local markets.
Parties involved were shown their own GPS tracks. Instead of just showing them on a screen, we used a small driving robot that would re-create the tracks on ground, but at a much smaller scale. As the robot drove, it left a trail of sand.