Amazon.com has positioned the Kindle DX as being great for textbooks. That was clear from their product announcement. It’s not the only game in town, however, and CourseSmart has developed an iPhone app which makes its 7,000+ textbooks now available on a teeny-weeny screen. That’s a big (no pun intended) issue, one would think, with trying to read a textbook on an iPhone. To be honest, that’s why the Kindle DX was developed; even the original Kindle / Kindle 2’s screen was not big enough. Besides the Kindle