Amazon Kindle 3 WiFi $65
I'm a huge fan of the Kindle for a lot of reasons--super-long battery life, small, light, replaces heavy stacks of books, simple interface, and tons of free books available. The new Kindle Fire was announced today, so I'm upgrading and selling my Kindle 3 Wifi in great condition. Screen is perfect--clean and unscratched, unit basically looks new except for some miniscule stress cracks at the bottom two bezel corners--purely cosmetic and hardly noticeable.
I've used it to carry around a library of free photo and classic books, and documents. For the price of a single book, you can have a Kindle.