This «histomap», made in 1931, is taken from a page in an old book. It’s an amazingly intuitive way to view the flow of world history over the last 2,000 years. To read the small font, click the map (and then click again to enlarge) for a higher-res version.
Nate Silver and co. are at their best with this analysis of domestic air travel in the US. Not only does this piece of work provide practical value to travellers attempting to minimise journey time, it also reveals fascinating details about US airlines and airports for the casual observer. As well as the wonderfully crafted interactive visualisation, be sure to check out the methodology section, where Silver delves into the hows, whys and wherefores of the investigation, presented as an engagingly written Q&A.