As computer processors have decreased in size and expense, mobile computing devices have become increasingly widespread. Designed to be portable, many mobile computing devices are lightweight and small enough to be worn or carried in a pocket or handbag. However, the portability of modern mobile computing devices comes at a price: today's mobile computing devices often incorporate small input devices to reduce the size and weight of the device. For example, many current mobile devices include small QWERTY keyboards that many people (especially those with poor dexterity) find difficult to use.