Hello,
I have asked for one of the eReaders for Christimas, and therefore I have been researching them. I went into Barnes and Nobles today and asked a load of questions. Basically, you can only download from their selection, about a million right now. They do have free wifi on the nook and you should be able to use it wherever there is a cell signal. When you purchase a book, most of which are $9.99, you can share it with other nook users for free as long as you give it to them via the nook within 14 days of purchase of the book. Some of the the old books, like Charles Dickens etc are free to download. Its about the same size as the sony. The only part of the nook that is touch screen is the bottom where the books are, the screen turns the page with the touch of the buttons. The Kindle from Amazon, uses any book that Amazon sells. It is bigger than the nook and Sony, but doesn't appear to be as user friendly as the nook and Sony, or so I've heard, although those that have it love it! I checked out the Sony today, its light weight, seemed easy to use and doesn't have restrictions to the books you want to purchase. You can buy any book from anywhere as long as the publisher has a download version for you. Both the Nook and the Sony have an MP3 player feature, the nook you need headphones to listen, Sony you don't because it has speakers! As far as I can tell the Kindle doesn't but i can't tell you for sure. Hope this helps, I am still searching but the Sony has a touchscreen version which I like and also a pocket version that has button control. The Sony's come in different colours, not sure about the others. That's all I know for now! Good Luck! The Sony is $299. for touchscreen, $199. for buttons, (pocket version), and Nook is $249. (Sold out, are delivering for Jan 15th), Kindle is $249, I think!