I was talking only recently about the Sony electronic ink (or e-ink) portable text reader: I discovered Sony have a rival in the Irex Iliad E-Reader, which is apparently already available here, at least on order from the continent.
It's not cheap, mind. You're talking the same cost as a cheapish laptop, which might lead some people to question why they might want one. The important consideration to keep in mind here is the screen technology. This is, apparently, nothing like the screen on your laptop or PDA.
When you read a page on a laptop, light is projected from the screen into your eyes. When you read a page in a book, ambient light is reflected from the page and into your eyes. The latter makes for a far, far easier reading experience - it's why we can sit with a book for hours and suffer few problems. Try reading a whole book on a laptop, and you won't last nearly so long.
Since the e-readers rely instead on ambient light, the appearance of text is intended to mimic the printed page, which is one reason why it's so expensive: new technologies only drop in price through mass production. I'm not about to rush out the door to get one myself just yet - cost and the fact it's a new technology are major and obvious factors - but people who need to work with a number of technical manuals in their work are going to love it. So are a lot of students, when they look at the cost and effort of acquiring physical textbooks over a period of several years of study and having them handy.
Another bonus is you can annotate and make notes in the Irex e-reader with a stylus. I think that feature is going to sell it to a lot of people. As an author, it means I can make corrections on a virtual page to an already existing manuscript without necessarily having to haul around either a laptop or a heavy print-out every time I want to work away from home.
Give it a couple of years, and these things will probably be cheap and plentiful. Newspapers are already investigating the technology as they gear up for the changes coming over the next few decades. You can take a look at a video 'review' of the reader over on youtube.
I don't mean to sound too gosh-wow about all this, but I think these devices represent a huge ground-shift for how we deal with text, and one that's coming soon. Personally I thought the Irex ran a little slow, judging by the video, but for one of the first devices of its kind on the market, I still think it's very impressive.