The question remains what to do with the inevitable paper book that remains?
One could gullitine (about $1.50 at Kinkos) and scan books for ones own use. The legalities of this are iffy, apparently. You would think it is fair use, just like making a tape or an electronic version of a CD that you own, but some people say no. This is a legal issue that needs to mature. In any case, retaining the book cover as proof of ownership and of destruction seems prudent. Japan, in contrast, has made it very clear that you can use a book you own any way you like, and I am told that there are more than 40 companies in Japan in the business of taking in your entire library and giving you back electronic files. These companies also exist in the USA; Blue Leaf is one. However, this is expensive: a review of the process posted on TeleRead paid almost $30.00 for one book.
One could also just refuse paper. I have to admit, that if I have no strong reason for reading a particular book and it isn't available electronically, I don't bother pursuing it. I feel resentful of paper books I own which are available electronically: how decadent is it to just buy the electronic version when it comes reading time?
However, at the end of the day, there are books which are important to my reading schedule and are only available on paper. I can see cases where I won't be willing to destroy them for the scanner and where it isn't worthwhile to send them away to Blue Leaf, so what to do? At first I kept my paper notebook for my notes on paper books. However, I quickly found that it is easy to hold the book open with the top of the iPad while making my notes in Evernote, so away with the paper notebook. And, frankly, it is still easier to carry that one paper book than the pile of them which was required before.