An interesting project from the University of Kent in the UK:
... by Kent University to assist in the Logins for Life project. I am seeking to talk with others in HE who might be considering researching, or already have researched, similar areas. The project is concerned with introducing a life-long digital identity for those who come into contact with the university. We will also explore the use of social networking technologies to access University services and look at the use of OpenID , Facebook Connect etc. as authentication methods. You can read more here:
Now I've written elsewhere about the problems of knowing who you are, or more accurately being able to demonstrate who you are.
Now increasingly, especially as we now have something like 500 million facebook members on the planet, 500 million hotmail/messenger users, and a little under 200 million twitter users, with about the same number of gmail users these services have started to be come the default authentication providers for a number of other services.
The only problem is that they don't have a great deal of quality control on their data, for example my cat has a gmail account, so one wouldn't necessarily trust having a gmail account to mean anything more than you exist.
However, if one can show that one has a gmail account and say a paypal account, we can presume that you are a reasonable and trustworthy person, if for no other reason that having a paypal account requires divulging verifiable financial information and the banks are quite good at checking that you are who you say you are.
So maybe that's the answer, allow people to create accounts willy-nilly, but for anything with access rights require proof of something such as a paypal account or other trusted provider ...