This is a great site dedicated to projects that are aimed at visualising complex systems. It seems that the more complex data gets, the more things resemble circles rather than the traditional top-down tree.

http://www.visualcomplexity.com/vc/

This would be a smart way for us to start thinking about linking / mapping information in systems that use tags and categories and the like. Or inputting the data, then looking at a circle-map of the actual connections.

So if you’re looking for a complex or beautiful diagrams, this is the place.

Map of scientific collaborations