[ghero]

Hmm, I have just thought another one:

(Can be any type of screen) about 4~6 inches (pretty much a phone/phablet, maybe a dedicated ereader), extreem high resolution (that is a phone size screen has a resolution about currently 10 inch high res tablet), with a special accessory to wear on the eye: telescopic glasses.

Hopefully, this telescopic glasses can adjust focus (either manually or semi/fully automatically), so when the user holds the reader, he can use the glasses to bring the small screen to nearly full view in front of his eyes, and read it as if it was a tablet. So, if this is done properly, we can just carry a very portable small screen, while reading magzines, pdfs/comics/technical docs on it, for phones, we can also enjoy viewing great HD videos and complex structured web pages. So, in such way, we might achieve both great portability and readability.

ADDITIONAL NOTE:
It would be fun if this telescopic glasses can also be used as a 3D glasses, so ppl can enjoy HD 3D movies/games/etc right off his phone/phablets (given that the screen also has support in displaying 3D).