At the lectures in london i picked up a few wesbites that seemed interesting.

EyeOverFishing shows how fishing has damaged the sea, and maps a route to a fishery where ocean life can replenish itself.
http://www.eyeoverfishing.org/index.html

Breathing Earth is a real-time simulation displaying the CO2 emissions of every country in the world, as well as their birth and death rates. It's quite daunting how fast our population is growing.
http://www.breathingearth.net/