Found this comment on a Boing Boing thread interesting. The original post itself (well, the poster it references) is stupid, but it inspired some interesting comments.

Studies have shown that students who used ebooks and ereaders retained a lot less information than those who used print books (I work in an academic library at a university that took part in the study). Ebooks eliminate the tactile part of sense memory. That is, where you saw the text on a page, and how far into the book it was, and if there were diagrams or illustrations or figures on the page or opposite page all plays a huge part in how you recall information. That all becomes fluid and relative in ebooks. While ebooks might be convenient for carrying around large books, you lose all relationship to them. It all becomes just a stream of words on a screen.

I’ve definitely noticed this as a general feeling. I enjoy my Kindle, but I do feel a bit adrift on the sea of “words on a screen”. I do miss the direct spatial sense of where I am on the page and the tactile sense of where I am in the book.