In the panel on Social Networking here at Net2.
Identity and profile sharing between sites is critical to using these tools in civil society. Planetwork where I am Network Director has been a long time advocate for open standards in this sector – the Augmented Social Network paper outlined the vision. We are excited about Open Standards from OASIS - XRI (I-names) and XDI to support identity and data sharing. They are cooperating with the with OpenID on Yadis too.
Planetwork is working on a project to build out open source, open standards based infrastructure to make it all work.
I am also working on i-tags to support identity in tagging.