Incidentally, even if you're not signed up for Google+, you may have noticed some changes in other Google apps, such as a new "People Widget" on the right side of the Gmail screen that offers information about your correspondents (similar to the Rapportive add-on), and a new black navigation bar on some of the other services, such as Google Calendar. Google is obviously gearing up for a big push.
Because the service is in such a limited release at this point, it's hard to know how useful it will be. If people sign up in droves, it will clearly become a must-have site. (You can get information about availability via the Google+ site.) If they don't, it will likely wither away.
But if you're interested at all in social networking, you should give it a try as soon as you can -- you may well find it a superior way to communicate with your friends, colleagues and acquaintances.
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