Displays requiring no power to maintain the image may be best suited for poster type displays and electronic books while in other applications the power consumed may be less important than the speed of image refreshment. Electrophoretic technology and the development of high resolution electronic 'paper' displays for example are contributing to device developments such as weather wizards and e-books. Emerging nanostructured electrochromic display technology with its color potential is promising to expand this market area further. Meanwhile, OLED displays may be challenged by development of nano emissive display technology based on carbon nanotubes. Markets for small and medium size displays are rapidly expanding with continuing expansion in the mobile handset segment fueling much of the short-term growth. Convergence in the mobile handset market is one key factor in growing demand for improvements in display technologies as these devices expand capabilities to add a wide variety of features from personal organizer to digital camera, video recorder, internet browser and so on.