Seth Sternberg, Meebo’s CEO, invited me over on Friday to talk about a new open standard that Meebo is proposing and supporting called xAuth. What does it do? It lets any client developer call it to find out what social networks you are on. This lets toolbar vendors, like Meebo, ship a better experience because users will only see sharing buttons and other details for the social networks they are actually already on. xauth.org and http have more information on this new API. UPDATE: Techmeme has more info on this at www.techmeme.com