Our smartphones and wearables will have flexible, rollable displays in the future. A bunch of companies are working on flexible electronics. This video from SlashGear shows a Samsung rollable OLED device demoed. Such a technology can be used to build a compact mobile device with a rollable display, in this case one that expands to reveal a 5.7″ panel.
This prototype was shown at SID 2016. Slash Gear has more on the story.