How has the world changed according to The World is Flat?

There have been many changes in the world that Friedman
discusses, but the major change is the one that give the book its title.  This is the
"flattening" of the earth.  What he means by this can be found on page 8 of the
hardcover edition of the book.  There, Friedman tells us that he came to realize
that

The
global competitive playing field was being leveled.  The world was being
flattened.

What Friedman is
talking about here is globalization.  He is saying that globalization has allowed
companies in all sorts of countries to compete against one another on a much more even
basis than they once could.  Things like the creation of high speed communication
(internet) and the boom in containerized shipping have allowed globalization to happen. 
These technological changes have led to a more competitive, "flatter"
world.

To Friedman, then, the major change in the world has
been the "flattening" of the world.