Light painting is a popular photographic technique to capture the movement of light in time and space. The light painting group on Flickr illustrates spectacular images created with this technique.
I like the light painting WiFi project by some Norwegian students. They created a light bar that responds to the signal strength of available WiFi networks at a location. The better the WiFi signal, the more lights on the bar glow up. Navigating through the city and capturing the light bar with their video cameras, they have light painted the WiFi signal.
This is a great example how invisible aspects of space can be made visible, in an aesthetically quite pleasing way. When I saw this, I was wondering how social aspects of space can be visualised with this or similar techniques. Location-based mobile phone apps and social networks such as Foursquare or Yelp tell us who hangs out where and which restaurants in town are preferred by people. How can such social footprints and collective spatial intelligence of the crowd be represented in a similar aesthetically pleasing, yet simple and intuitive way?