The more I think about this "problem" too, the more it goes back to the question of why do these sites need my information, and subsequently what way can they verify my identity?

We need a better web of trust where another service can verify the identity of me as a user. Already with the likes of Chrome, much of my logins are already auto-filled meaning the browser is already happy with my identity, why can't part of this be used for signups. We have second-factor authentication, again why can't we leverage this to verify I am the real person. Between the browser, a third party service and the receiving service we can securely verify an identity without the need for passwords, email addresses and real names.

I thought of that too, and it would not be preferable to have shared logins, or an automated system in place for registering on e-commerce sites, or sites where money is moving in them. One could argue that a large portion of websites have money moving through them in one form or another, but I don't have the numbers / stats for that. This would be more for general purpose sites that have wall-gardened information, and also for sites that have arbitrary registration forms which exist for all the reasons (or lack of reasons) I outlined in my post.

Fair enough. Maybe some examples would help me understand.

I do get that registration can be a pain. But what I'd want wouldn't be a skeleton key, but rather a personal master key. Logins using Facebook and Google have become common.

But, being a privacy geek, I don't have accounts. And I definitely don't do cellphone authentication, because that is nontrivial to anonymize. However, I would want two-factor authentication. That's the tough problem, I think.

In order to use Facebook or Twitter to find information on those services, one must create a new account and divulge all sorts of personal information.

accounts that are used by groups are harder to track and pinpoint, and their site usage will likely be too random to glean meaningful data from them.