This is a screenshot from a really neat animated map by Ben Dilday that draws the USA over time, with each state popping in to existence the year it joined the union. Go click on this link to check out the animated original source!
|click for the animated source!|
Of course, one can't talk about data visualization in D3 without mentioning the incomparable Mike Bostock, it's creator. His work is amazing (check out this awesome gallery). In particular here's a few animated or interactive maps he's created that stand out: