Unix Linux or any paperback manuals

Or any paperback book covering the IT field, is usually heavy and takes a lot of the free space in
my backpack. I have tried to use the pdf files from the books, to read them from my mobile phone or pda, but the starring at colorful screen makes my eyes tired, so I bring the book instead.
Finally, Sony has a piece of hardware that could resolve the "problem". The have developed the Sony PRS-500, with E-ink technology from MIT. This peace of work could save my back and eyes. The E-ink uses micropulses and black and white nanoparticles to take care of the issues with reading tons of manuals. A full battery lasts about 7.500 pages, or 25 books. If there is good search feature, this baby rocks! Check it out, at sonystyle.com