The Acer Iconia is two tablet screens hinged together that run on a standard Windows OS. They can be linked like one big screen or act like two independent screens.
DUAL SCREENS
Nintendo's handhelds have proven the effectiveness of two screens, and now at least one phone is following suit. You can put most anything on either screen, and the screens can be independent or connected. Two screens lets you do some basic functions on the go, like watching tv while web browsing or viewing pictures on one screen while compiling a photo album on another. I have often wished my laptop screen was a little bigger, but that just means a bigger laptop to lug around.
KEYBOARD
When you rest ten fingers on the bottom screen, a keyboard automatically appears. Being completely a touch screen means that it's somewhat difficult to type on since you can't feel the individual keys. However, you can easily load other types of keyboards.This is impractical for most, but would be amazing for typing in Japanese. I always have to mess around on windows to type in Japanese with my keyboard, and that's still a bit odd because you have to type everything in romanji. I think this is why there are so many Japanese instruction books that exclusively use romanji. You can also choose to write on the bottom screen, and their recognition software will turn it into type.
Sure, you can write on tablets, and buy these to use a pen on your computer, but with the iconica you can use the programs you cant get on a tablet and write on the screen like you can't on (most) desktops. I previously wanted the Dell Inspiron duo. The idea is basically the same, except with a rotating screen creating a tablet to write on. However, I am concerned about the hinges that spin the screen. I am not claiming they are flimsy or would break easy... But if they did break, I think you would be screwed. And, if I could write directly on the screen, that may eliminate my need for sketchbooks altogether. Not that I will stop buying them.
This video is for a different device called "Kno" and is specifically designed for text books and note taking. I have no seen any use of the Iconia sideways as a book reader, but I hope that it has this functionality, or could add this functionality. Sure, it would be a bit clunky to hold it sideways, but carting around books, sketchbooks, and a computer is a bit clunky too.