Facebook Games for Learning?

So it seems that many people play Facebook games - Farmville, Mafia Wars, etc. It is also now apparent that many people despise the constant barrage of updates they receive regarding their friends automated game updates. I must admit that I am one of those that gets tired of constant updates regarding my friends gaming progress. I actually joined a Facebook group that was titled something like "I don't care about your farm, or you mafia, or your fish." However I just read an article on CNN.com regarding these types of games. Link to article here. After reading the article I have a better understanding of what makes these games popular. They are simple and they are social. They are social in that sometimes people work together or help each other accomplish things, and at other times people are locked in fierce competition. My question is this. Could an environment like this be created in order to help students become better at math or reading? Could a game be created that rewarded people for solving math problems or improving their reading comprehension? I don't see why not. Just a thought.