I think I see the physical appeal of one card per book, but I actually want to be able to search through book text from all my books, which is harder to do if they're not all in one storage bucket. Sometimes I can't remember where I read some particular little snippet of prose, and I want to try to find it. (Kind of like when you get a bit of a tune in your head and you're trying to remember the rest of the song... well, it may not happen to
you, but it happens to
me, anyway.)
Now, if I had WiFi that worked everywhere, I could use Google Book Search to find those books, I suppose. At least, for those books in Google, which isn't all the books I own. (Neil Stephenson's
The Diamond Age isn't there, for example, which strikes me as particularly ironic.)
Also, I own thousands of books. Each has distinctive cover art and spine text, so it's not too terribily difficult to find them if I know what I'm looking for, but I think it would be harder with something like a CF card. I remember flipping through large collections of 3.5 hardshell "floppies" having trouble finding what I was looking for. Credit style cards, memory sticks, etc. would be no easier. I'd rather have searchable nested folders and a good "find" function.
Bottom line, I really think publishers of all kinds need to get over this DRM nonsense. The music industry has not collapsed since the consumerization of the CD burner or the MP3 player. If you have good content, people will pay for it. I'm with yvanleterrible on this. But that's an old argument, and I guess we all have our opinions on it, which are probably not those of the publishers.