Motorola shows off its concept rollable smartphone

We've seen rollable device concepts from companies like Oppo and TCL, and LG was even working on a commercial rollable smartphone until it quit making mobile devices last year. Now, Lenovo is showing off a laptop with a rollout display, while its mobile division Motorola has a roll-out smartphone -- and they look like some of the more practical efforts yet. The phone starts out at a very pocketable 4 inches high, but with the click of a button, the OLED panel extends to a normal-sized 6.5 inches...