CircleID

I've spent a lot of time thinking about online identity.  David Chaum has written extensively, (and brilliantly) describing ways to provide irrefutable evidence of, e.g. citizenship or the right to drive, while preserving anonymity. 
In my anti-spam work, authentication and reputation of identity is critical.  We develop efficient and robust methods of authentication and reputation, such as CSV.  Most of the concepts behind CSV are applicable not just to email spam, but to all spam, such as SPIM, wikispam, blogspam, etc.  While they are not useful where identity must be tightly tied to an individual, there are many cases
There are different levels of authentication, analagous to the levels of authentication provided by PGP/GPG, S/MIME, DKIM/DomainKeys, CSV, etc (which vary depending on how they're used).  SpamAssassin rules and Open Proxy DNSBLs, for example, are already widely used to prevent non-email spam.
Unless we want to help build a police state, folks must continue working on implementations other than ones that just tie an online identity to a gov't ID.  I think it's great that this is continuing.