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.

Why? Because these social networks are a unique way of broadly communicating real-time messages to the audiences they want to reach. They can write a message anywhere, anytime, and share it with interested parties without any public relations meddling, speech writers, airplane travel, canned videos, or voicemail messages. Now their words are much more authentic and can be remarkably empowering. Social networking is also flattening organizations by distributing access to information. Everyone is equal on the social network. The biggest threat presented by social networks is to middle managers, who may become obsolete when they are no longer needed to convey messages up and down the organization. The key to success in the social networking era is to empower the people who do the actual work - designing products, manufacturing them, creating marketing innovations, or selling services - to step up and lead without a hierarchy. By Bill George