A brilliant economist, and one of the greatest advocates for human liberty of our time. You will be missed.
UPDATE: Remembrances from around the web: New York Times, Brad Delong, author Steven Levitt, Marginal Revolution, Inactivist, Coyote Blog, a collection of Friedman quotes, Asymmetrical Information, To the People, Distributed Intelligence, Catallarchy, Virginia Postrel, Cato Institute, Hit & Run (including links to several Friedman interviews), Positive Liberty.
Besides being one of the most influential economists of the last century, Friedman was also a champion of (among many other things) school choice and a volunteer military. He is credited with having a hand in ending the draft.