It's not so much social networking sites that would be great, but the possibility of free interactive education. The quality of teaching that most (poor and black) South African school children are subjected to is shockingly poor.
As much as I agree with you, that is not where the cool stuff will happen. Sad as it may be, innovation on the web has never really been centered around education. And as far as the goverment is concerced, I don't think that smart ways of using technology to improve education are on the cards soon.