A few months back Philips announced a prototype device using its rollable display. During the 2006 International CES the company was showing the prototype and a small device that continuously folded and unfolded a display, showing the Control Panel of a Windows Mobile Pocket PC.
While this would be neat - can you imagine how much thinner and the power savings if a Pocket PC or Palm device could be using this display? - it may not be feasible for now, since the rollable display is black and white only, and not touchscreen (but I am sure things can change in the future)
The Polymer Vision PV-QML5 is an ultra-thin (100Ám) QVGA (320 x 240 pixels) active-matrix display with a diagonal of 5 inches. When not actively used, the display can be rolled up into a small housing with a radius of curvature of less than 7.5 mm. With four gray levels, the monochrome display provides paperlike viewing comfort with a high (10:1) contrast ratio for reading-intensive applications.
Using a bi-stable electrophoretic display effect from E Ink Corp., the display consumes an exceptionally low amount of power. It is thus ideally suited for mobile applications.
Here are some pictures and a closeup image of the display: