Textbooks--Paper or Digital?

Basic belief: Technology in the classroom should be utilized to facilitate learning, not just for its own sake. Thus, I turn a skeptical eye to the "wow" elements of technology, assuming them to be useless until proven otherwise. E-books? The texts I coauthored come that way, but for now I'll assign the paper versions.

Where is the cheap, portable e-book reader? Until every student has one, I am not going to require students to sit in front of their computers to read the book. So much nicer to curl up in bed and fall asleep with a good textbook :-)