There's a new book from former WIRED editor Chris Anderson specifically on the topic of entrepreneurship in the 21st century. Makers: The New Industrial Revolution investigates the development of entrepreneurship in the software industry, where vast business empires have been built that run much of the world today.
Then he asks a truly profound question:
What happens when the Web generation turns to the real world?
This is inevitable given the existence of hyper-entrepreneurs and the near emergence of easy 3D printing in the next several years. Anderson contrasts the ease of today's development with that experienced by those in the mid-20th century. It's a different ball game now as he examines the potential results of the collision between 3D printing and similar personal manufacturing processes with modern methods of building businesses.
What will 21st century entrepreneurs create when machines are capable of building a multitude of object geometries in many different materials?
Find out by reading Anderson's book.