During Nodecamp 2011, the members of 9elements - a small company dedicated to web applications - were eager to present a live tracker built with node.js. Inspired by Paul Butler's Facebook Map, the team decided to go with data from img.ly, a popular social photo sharing service that happens to be the image service of Twitterrific.
The visualization they ended up creating shows the live activity of visitors on img.ly as a series of dynamic arcs across the globe. Each arc starts with the location of the visitor and ends with the location of the image the visitor is looking at.
As the authors explain, they were particularly interested in disclosing hidden connections within img.ly: "There are already many apps plotting visitors on a map, so obviously this was not very interesting. We were interested in connections, and basically there is already a very important type of connection on img.ly. Whenever you call a picture on img.ly, you create a connection to the user who posted it. We can apply this idea to location, thus all we had to do was to connect the location of visitors with the location of the picture they're viewing. That's the idea."