I have noticed that I am going through books a lot faster since I got my nook. I think it is a combination of faster and easier page turns (as opposed to flipping pages on a book), the size of the nook allowing me to carry it to places I normally wouldn't take a regular book to, and lack of a visual indicator of how much you have been reading (bookmark in a real book).
Some of it my be that the last few books I have read were very good and engaging. No matter what the factors are though, what it adds up to is more money going to B&N!
Anyone else noticed this?