Here's an interesting visual art project that reveals the invisible landscape of our WiFi networks and explores the effects that these intangible phenomena have on how we experience products and cities. The "Immaterials: Light Painting WiFi" project was created by visual artists Timo Arnall, Jorn Knutsen, and Einar Sneve Martinussen.
In order to create a visualization of the WiFi terrain, the artists created a 4 meter tall pole attached with lights that lit up according to a location's WiFi signal strength. Then using long exposure photography, they were able to capture the cross sections of a network's signal strength as the pole was moved across a landscape.
The resulting images are like cross sections of the WiFi signal topography materialized in the actual landscape. Having photographed these topographies in various locations, they noticed enormous differences in the way networks spilled out from large institutions versus, say, an old apartment building and that the behavior of the network very much depended on the architecture and how the city around it is built.