Twenty-five years ago, business visionary Charles Handy described the emerging Shamrock Organization as the business structure of the future. It consisted of a tiny core of permanent workers, a large group of temporary workers, and a versatile set of contractors working for many organizations at once. Today, enabled by the Internet, that third component has become a huge, indispensable, and rapidly growing part of the U.S. workforce. What is the nature and role of this contract work force? What does it portend for companies, individuals, and society in the years ahead? How will it impact your life, career and investments? We’ll explain.