Not much on this site at the moment, but keep an eye on this one.
With all the talk of opening the social graph we will need an open protocol to do proxy authentication, where users log into the data provider and not the mashup. Don’t confuse this technique with OpenID; it’s almost the reverse. OpenID lets you control who owns your login credentials, and this method let’s a mashup use your remote data without knowing your login credentials. This protocol definitely needs a generic buzzword–I’m gonna call it AuthProxy until someone more important than me comes up with something better.
Development-wise we have several solutions, from Google’s AuthSub and ClientLogin to Yahoo!’s BBAuth. If you’ve ever played with a site that does stuff with your Flickr account, you’ve used AuthProxy. It usually involves a username/password login on the data provider’s site, which then redirects back to the mashup with a token. The token is passed back to the data provider’s via an API call, which allows the mashup to access the user’s personal data, but without sharing the user’s login credentials, or sometimes any identifying information.