I wanted to get some advice from those of you who use E-Readers while out. They make more sense from an energy perspective as I've heard E-Ink displays are much more power efficient than tablets are. Considering some of them have the ability to take an SD card to expand space, they can allow you to take multiple books and save on weight.

What models do you guys use, and what is a good option for a budget e-reader that won't snap when I put it in my pack?