Leaders like IBM's Sam Palmisano, PepsiCo's Indra Nooyi, Apple's Steve Jobs, Microsoft's Steve Ballmer, Carlson's Marilyn Nelson, and Harvard Business School Dean Nitin Nohria are all active social network users.

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