I just ran across this site. It looks very interesting but unfortunately the game itself is over. (at least for now).
From the site... Evoke is a ten-week crash course in changing the
world.It is free to play and open to anyone, anywhere.The goal of the social network game is to help empower young people all over the world, and especially young people in Africa, to come up with creative solutions to our most urgent social problems .EVOKE was developed by the World Bank Institute, the learning and knowledge arm of the World Bank Group, and directed by alternate reality game master Jane McGonigal WatchWhat is an EVOKE? on Vimeo.