A very slick Flash visualization of CIA world geographic/economic/demographic data called the World Factbook Dashboard; it’s in Flash, so iPad users are out of luck. ;-). Start out with a map of the world, with colors denoting country population:
You can adjust color for population ranges by moving the sliders at the bottom; plot a different index by clicking its name at the top, like infant mortality:
Plot multiple characteristics by clicking on the Treemap tab at top to get a “cartogram”-like view, like this plot where size is proportional to population, and color denotes infant mortality:
Click on a country in World Map or Treemap mode, and get its worldwide ranking for various parameters, as well as graphic comparisons to neighboring countries for selectable parameters, in a pane at left:
Lots more stuff to check out. Via Download Squad, which has a ten-minute video demoing some of its features.