Electronics is catching up with newspapers. Really. Late last month in Tokyo, Sony took an important leap in this direction by introducing Librie, an e-book reader. The device, which costs $370 and is about the size of a paperback, holds the equivalent of dozens of books, which readers can download from the Web for $2.20 each. Although it's available only in black and white, Librie has the most important characteristic of paper: it reflects natural light. That means it can be read on sunny days or viewed from any angle. You can even choose your own font size. Sony expects to sell 5,000 units a month. Is this finally the beginning of the end of paper?