There a lots of interesting points to see in there :
- one can easily spot the future public retirement plans problem in Europe (with more and more elderly people ). See here for example : http://populationpyramid.net/?country=Belgium&year=2050
- I am still wondering what is happening in countries like Qatar in 2010 (http://populationpyramid.net/?country=Qatar&year=2010) How come there are so many more men than women ?
- Near 1950 in Europe, you can spot the "dent" made by WW2 in the population, plus the baby boom. Example : http://populationpyramid.net/?country=France&year=1950
- It is already interesting to compare the shape of the pyramid for countries like Afghanistan in 2010 (http://populationpyramid.net/?country=Afghanistan&year=2...) VS the US in 2010 (http://populationpyramid.net/?country=United_States_of_Ameri...). One can easily see the difference in development, to say the least.
And so on...