Sony and Nook both support the epub format which will allow you to borrow books from your public library and they will delete themselves after 21days. With the Sony and Nook you can also download free ebooks from google several classic books as well as old trapping, cook books, hunting and other survival related subjects are there free for the downloading. I dont like the Kindle for the reason that they can DELETE your books off your machine without even notifying you, they say they wont do it again but the fact that they can if they want to dont sit well with me it also means that they can see what else you've been reading which means if you've been reading army tech manuals that you've bought on pdf format they could go "oh my god he's reading about weapons and tactics and military gear" and no telling who they would report it to.