This was the year social networks became normal. Next time you're in a crowded restaurant, close your eyes and listen to the chatter around you. Count how many times you hear the word "Facebook" in an hour. This year, the number of people on Facebook reached 800 million. Remember when it was for college students only?
Google+ also launched this year. It's not just a new social network; it's what Google+ chief Vic Gundotra called "the + part" of the new Google. Every part of the Google experience, especially search, involves social connections now. And Twitter was no also-ran in 2011. It became a system-level part of every iPhone, iPad and iPod Touch on Apple's new iOS 5. In the ongoing war of the social networks, this year's pivotal battles were over three key territories: identity, location and sharing. How did it play out?