A few people have asked about my Kindle. I am certainly glad to have it, although it's hardly a necessity like bread or wine. My wife encouraged me to buy one, and since of course I am a sucker for self-gratification, I spent the 350 or so bucks. It means buying fewer books, but that will never stop completely. Kindle is a great device with a non-glare screen and reasonably easy navigation; open a file, and you go right to the place you left off. Downloads from Gutenberg are free, and current books cost no more than $10 (that I know of) from Kindle. The complete works of Mark Twain set me back about $2 from Amazon.
Is it economical to buy a Kindle? It depends on how many books you normally buy. It's going to be a long time before my gizmo "pays for itself," if it ever does. But as grownups' toys go, it's a good one.