I have always loved seeing political maps that show the empires over the centuries, and their territorial expansion, their rise and fall.
The map of the British empire at its zenith, the Islamic empire at its peak in the middle ages, were fascinating.
Someone (Randall Munroe) came up with an idea of cartographic-ally showing the sizes of online web 2.0 communities. One in 2007 and the other in 2010. Pretty interesting to see the change in the internet landscape in three years – how some social networking websites have dwindled and some others like Facebook have grown exponentially.
The actual maps are here:
via Digital Gravitas