There's a proposed RFC (which I believe will be accepted before the end of the year) which provides a standard (assuming acceptance) way to transport identities

There's a proposed RFC (which I believe will be accepted before the end of the year) which provides a standard (assuming acceptance) way to transport identities between services on the Internet - http://www.simplecloud.info/ http://www.simplecloud.info/. It's backed by some pretty big players and we're adopting it as the new version of one of our identity APIs at Penn State. There is currently no mechanism for deciding which parts of your identity are available to different people, and retrieval of anything not marked public would require that they identify themselves. I think the ideas below are great, and adding your friends, business contacts and acquaintances to different circles/spheres/lists is an easy way for you to manage them. The hard part (I think) is that identity needs to be federated somehow so that you know who is asking for your identity and therefore which fields to provide (A&A strikes again). I'd encourage everyone who cares about solutions like this to read the specifications I've linked to, then read and participate in the mailing list ... the discussions are amazing.