As glued to the net as we all are, there's vast quantities of content that is not available online.
The Kindle has a built in cell receiver so that you can wirelessly browse, preview and purchase books using one-click.
Kindles can read a variety of non-proprietary, non-DRM'ed formats. They read TXT, HTML, JPEG, and non-DRM Mobi files directly.
A cheap casioppeia allows me to read ebooks around 2001.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.