A Practical Mona Lisa: Anyone who is interested in graphic art or the visual representation of ideas has probably encountered Minard's Map. It is a graphical depiction of Napoleon's invasion of Russia and retreat from Moscow. It is generally thought of as the Mona Lisa of graphic data depiction. You can read this article about it for more background. But start by taking a look at this readable graphic to get a sense for how information-packed, yet perfectly clear, it is. If want to look even deeper, this site has many variations and rethinkings of the map.