Facebook has woven its way into the fabric of everyday personal and business life. And the social network has had to adapt in response to challenges from a variety of upstarts. Foursquare, Google+, Groupon, and Twitter are all trying to give Facebook a run for its money. But the service shows no signs of slowing down, with Facebook recently surpassing 750 million users. Mark Zuckerberg and friends are constantly rolling out new features, from Skype video calling to a new landing page for businesses.
