The UN World Food Programme has a video game out to educate people about different aspects of emergency food relief operations. it looks well done and runs on both Macs and PCs, with the only hitch being the several hundred megabyte download.
More information at WFP Foodforce – The Game, The Reality, How to Help and Wired News: U.N. Game Wins Hearts and Minds.
See also Greenflame: Education Arcade, day 1 for some links on edu-gaming.
On a related theme AKMA has some thoughts on religion in online multiplayer games and virtual worlds. See AKMA’s Random Thoughts: Faith In Terra Nova.