what is a book?

Just what constitutes a book these days. I have shelves full of paper bound with glue and thread, covered in ink... I know those are books. Some of you read on Kindles of Ipads. Are those books? Cheryl and I listen to "books" on disk as we commute back and forth to Santa Barbara from Buellton along the Gaviota Coast. Are those books?

We've read or listened to some wonderful books recently and I've found myself wanting to blog about a few or at least mention them in my blogs but wasn't sure how. Should I say, "we're reading The Things They Carried" or do I say that "we're listening to...?" Frankly, something inside me is a little embarrassed to say that we're listening to whatever book as if that is cheating somehow. And in some ways it must be a different experience. The reader does impose himself or herself into the text and does interpret it with their inflections and tone of voice and somehow that does remove part of the experience we get when reading a bound document, providing the voice, the inflections, in our minds. Clearly it is not as different an experience as watching a movie made from a book, but it is still different in some way.

How significant is that difference? Is that audio book, whether on disk or MP3 or whatever, still a book or is it a different medium altogether? And how about an i-book? What do we lose when we don't hold the paper and flip the pages? What do you think?