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 can be the killer app of the future. Properly adapted to an earmounted multifunctional device (micro, speaker. Cam, display) and connected to a wearable power generation system (PV films in the clothes and embedded batteries).
It has portability, big screen size, PC working capability. If mass produced it can have an affordale price ($250) to be accessible to most consumers.