I've blogged here several times[1][2] about using laptops and netbooks instead of paper books. Here's an interactive textbook platform for the iPad called inkling. I took a look at the economics textbook, and it looks very good, but remember, as good as it is, Inkling is in the first wave of implementations of any kind of software for the iPad. In 2 or 3 years, the possibilities are endless. Take a look at the video, too, it is inspiring. Now if we could just get the students to read the textbook, in whatever format it came, we'd be sorted!