In case you missed it, the Google Doodle for today (at least at Google.ca) commemorates the birth of Gerardus Mercator on this day in 1512. Mercator is well known for his new and revolutionary 1569 map of the world. While his projection has, of late, come under criticism for its distortion of the areas further from the Equator, making countries in the northern hemisphere appear more spatially dominant than they are, at the time of its creation, it was essential for sailing ships. With its straight-line grid of latitude and longitude, constant bearings of sailing ships could be shown as straight lines on the map. Due to its importance at the time and for decades (centuries?) thereafter, the Mercator projection is the most common map projection around.
Now, if we can only get Google Maps and Bing Maps and all the other online map companies to move away from the Mercator projection, we might finally get a more realistic view of the world!