Based on this popular post around the idea of how you can fit the population of the United States into various countries. The map above looks at how you could fit the population of North America into Europe, and still have several million people left over.
Starting today Lithuania becomes the 19th member of the Eurozone. All countries that join the EU are supposed to work towards adopting the Euro (with a few exceptions discussed below). The map above shows which European countries are currently using the Euro. They are: