Here's a Google Doc that is being created about Google+ It's titled "A Collaborative Document: (or how 120+ people wrote a book at the same time)"
Despite the title, it's actually a guide being created by Google+ users on how to use Google+. And they're using Google Docs
to write it, of course. This is a nice illustration of the post I made on the first day about how Google+ is making Google
stronger. Read that here: https://plus.google.com/112063946124358686266/posts/SrQrSSXeViq
It also shows the way in which Google+ users are similar to Facebook users: when given the tools, they will contribute positively to further the service. I mention that point about Facebook's platform strategy in this post about Zuckerberg's first public response to Google+: https://plus.google.com/112063946124358686266/posts/g2zmxn1LmtX
In the past, I've used Google Docs mainly because I wanted web access to files. I've never collaborated on it, and now I'm hooked on doing that. Google+ is making me use Google products that I formally only had a slight interest in. In the past week, I've started to toy with Blogger & Picasa. Why switch to Gmail, I used to think? Yahoo will do just fine. I've been using Gmail more and more.
Btw, welcome new users, I see the invites are open today -- read this guide for tips.