"Flare is an ActionScript library for creating visualizations that run in the Adobe Flash Player. From basic charts and graphs to complex interactive graphics, the toolkit supports data management, visual encoding, animation, and interaction techniques. Even better, flare features a modular design that lets developers create customized visualization techniques without having to reinvent the wheel."
(UC Berkeley Visualization Lab)
"Circles are sized by the number of medals that countries won in summer Olympic Games. Use the slider to view past Olympics, or click on a country to display a list of its medal winners."
(The New York Times)
[Interestingly although the map appears to have been created as a simple representation of the global medal tally the map also quite eloquently reveals aspects of the changing economic fortunes and political leanings of particular countries. Note for example Germany''s Olympic success prior to the Second World War and Eastern European success during the Cold War.]
Leibniz Laboratory (IMAG Institute, France)
A graph is a very simple structure consisting of a set of vertices and a family of lines (possibly oriented), called edges (undirected) or arcs (directed), each of them linking some pair of vertices. An undirected graph may for example model conflicts between objects or persons. A directed graph (or digraph) may typically represent a communication network, or some domination relation between individuals, etc.
The branch of mathematics called Graph Theory, is useful for understanding the method of associating pages within an Internet site.