For my “History and Future of the Book” course, I’ve been using a Kindle that my university library purchased on my request. Gizmodo has a good article on the digital rights associated with Kindle e-books.

In the fine print that you “agree” to, Amazon and Sony say you just get a license to the e-books–you’re not paying to own
’em, in spite of the use of the term “buy.” Digital retailers say that
the first sale doctrine–which would let you hawk your old Harry Potter
hardcovers on eBay–no longer applies. Your license to read the book is
unlimited, though–so even if Amazon or Sony changed technologies,
dropped the biz or just got mad at you, they legally couldn’t take away
your purchases. Still, it’s a license you can’t sell.

But is this claim legal? Our Columbia friends suggest that just
because Sony or Amazon call it a license, that doesn’t make it so.
“That’s a factual question determined by courts,” say our legal
brainiacs. “Even if a publisher calls it a license, if the transaction
actually looks more like a sale, users will retain their right to
resell the copy.” Score one for the home team.