Jane McGonigal is, of course, the doyenne of ARGs and, along with Elan Lee, their chiefest proponent and creator. She is also, of course, more than slightly nuts; in her TED appearance, she seems to argue that ARGs will save the world. "LOL" seems a not inappropriate response.
If you follow the field at all, you will already have heard of Evoke, a World Bank-funded game set in 2020, when ecocatastrophes of various kinds are in progress.
Ostensibly, its purpose is to crowdsource solutions to global problems, with 'winners' appearing at a World Bank event later this year to pitch their 'solutions.' It's not much of a game qua game; unlike traditional ARGs, there's no prescripted solution to puzzles, so it's more a chatterblog about global issues, which is mildly interesting in its own right, of course.
Enter Katharine Neal, an occasional commenter here who was, not incidentally, part of the team that developed Escape from Woomera, a game satirizing Australia's policy of incarcerating political refugees.
In response to McGonigal's ARG, Neal has created one of her own -- Invoke, wherein your mission is to "whitewash the World Bank's reputation" by playing. It, too, is not much of a game -- again, mostly a chatterblog about the weekly "missions" posted in the form of a nicely-drawn comic.
Unlike McGonigal's game, however, Invoke is pointed, nasty, and quite funny.