I just finished reading my first real ebook. Wil McCarthy made his, popular, Hacking Matter available for free. Unfortunately, it appears to have been slashdotted, so you'll have to try back later.
The experience of reading this book is mind bending. Imagine living under a roof that can morph from a 40%+ efficient solar cell to a battery, to a skylight. The windows move when and where you move at your whim. When the sun sets, the walls, ceiling, floor, and tables begin to glow providing all the light you'd need. Cars, chairs, even people hover. These are just some of the things described in the book that have an analogue to today's lifestyle. All these will soon be made possible by a man-made substance that has been dubbed Wellstone.