The Lionel Pincus & Princess Firyal Map Division of the New York Public Library has released more than 20,000 copyright-free maps & cartographic resources.
Maps can be viewed and downloaded via Map Warper.
(Source: New York Public Library)
How much have we polluted? is a map visualization of global carbon dioxide emissions.
The map allows the user to view the yearly per capital and total CO2 output of individual countries around the world.
Data behind the map is from 1960 to 2008, which enables the user to see which countries have increased or decreased their CO2 emissions over time.
The map also allows the user to compare two countries at once.
(Source: Google Maps Mania)