David Wiley is part of a startup called FlatWorld Knowledge. Their aim is to publish textbooks free of charge online, with users paying for the printed version if they want it. But it goes beyond this and really gets at the role of the textbook in education. For a start the educator can edit the text book, so their students get the version relevant to their course. And then there are tools for working with other students around the text. People can sell content (and services I guess) also in a marketplace.

There could be some good synergy with the social, multiple tools approach of socialearn here.