Why is another world popoulation map website Cool? Because on GunnMap, by Gunn Interactive, you can load your own data. There are a few example data sets preloaded like population, GDP growth, military spending and birth rate, but the best part is that you can paste in your own data to create a custom world map.
Here's a quick demo video from Arthur Gunn on how to use the site by pasting in data from the CIA website to create a new map:
Thanks Paul for the link!