Still pondering buying an e-reader. It's the idea of having it to read while I'm on the elliptical that is most appealing, since it's difficult to read most books that way (they won't stay flat). Also, handy for trips when I would need to carry more than one book (which is most of them). Have been doing some price comparisons of paper books with e-books. The range is wide and not very predictable.
A second reason is that I want to accumulate fewer books. There are still lots of books I would prefer to have it paper (just to have, easier to lend) but a fair number I wouldn't mind having electronically because if I had them in paper I would just get rid of them after I'd read them once.