A pen-sized smartphone equipped with a stick out rollable touch screen system may revolutionize the entire way that we communicate and utilize our multimedia devices (smartphone, tablets, pc etc). This could be the killer app of the next future.
Properly adapted to an ear-mounted multifunctional device (micro, speaker. cam, display), and connected to a wearable power generation system (PV films in the clothes and embedded batteries), it could allow maximum portability in minimum space for entire system, with a large size screen.
It would include speech-recognition and voice commands for most functions.