An article in the Sunday, August 9th New York Times by Tamar Lewin takes a detailed look at the move to digital textbooks that is gaining traction around the country.
The story quotes Marina Leight from e.Republic's Center for Digital Education and Converge magazine and gives a good overview of developments in the still nascent but probably inevitable move away for traditional text books. This trend got a big shove earlier this summer when Governor Schwarzenegger announced a California initiative to move to digital math and science resources for students.
Not mentioned in the NYT article and worth a look: Scott McNealy of Sun Microsystems has been an outspoken champion of free open source educational resources for many years. More recently, Aneesh Chopra, currently U.S. Chief Technology Officer, was working towards a physics digital flexbook in in his previous job as Secretary of Technology for the Commonwealth of Virginia.
Chopra outlined his views on Virginia's digital flexbooks in the video below, filmed in the fall of 2008.