I heard in the latest Matt Cutts webmaster video that Google is trying to shift towards a non-anonymous web with the use of rel=author. However, how many people really use Google+?!?!

I, for example, use Facebook and Twitter, but not Google+. Can I make use of rel=author or is it reserved exclusively for Google+ users?

From what I understood (when I started using it) it's linking only to public Google profiles (with a personal picture). May have changed in the meantime.

Although I have a Google+ account, and share editorial links there, I do not actually use it as a social network like I do Facebook and, to a lesser extent these days as 140 characters just ain't enough, Twitter. In fact, I don't know a single person who is using G+ as their primary social network or even secondary for that matter. I think LinkedIn probably has more genuine participation, and that's saying something. Truth is that Facebook has the momentum and while plenty of us criticise it, quite rightly, it's hard to start with a new social network in any meaningful way when you network of friends is still on Facebook.

Pritaeas, it definitely still does that, but I was wondering (and perhaps, hoping) that it expanded its usage to Facebook and Twitter to make it more, well, practical.