I received a Nook for Christmas and am in love with it! As I was wandering around the Barnes and Nobles website, I ran across something that was developed for the college level student but, if used for trade books, etc, could have amazing applications in middle and high schoool. check out Nook Study. They have more than 1 million (yes, 6 zeros) FREE books, so there is probably some textbook or trade book out there that someone can use.
Imagine buying ONE trade book and making it accessible to ALL your students to read and use in discussion in class... pull it up overhead on a laptop or e-reader and go for it!