Social networking is the most significant business development of 2010. During the year, social networking morphed from a personal communications tool for young people into a new vehicle that

Social networking is the most significant business development of 2010. During the year, social networking morphed from a personal communications tool for young people into a new vehicle that business leaders are using to transform communications with their employees and customers, as it shifts from one-way transmission of information to two-way interaction. That's one reason Time magazine just named Facebook founder Mark Zuckerberg Person of the Year. A year ago, many people poked fun at Facebook as a place where kids shared their latest party news. Today more than 800 million users worldwide are active on the site. The most rapidly growing demographic is people over forty. More than 500 million people spend at least one hour a day on Facebook. Approximately two hundred million people are active on Twitter in spite of - or because of - its 140-character limitation. Another 100 million use LinkedIn. None of these social networks even existed at the beginning of the decade. By Bill George