A newly revealed patnent application (March 13, 2007) from Apple which describes dynamically changing keys using OLED (organic light emitting diodes) on each key face. This is similar to the widely-publicized (but not yet shipping) Optimus keyboard:
By modifying the key faces, keys could reflect the current functionality, rather than relying on memorizing shortcuts. When introducing the iPhone, Apple boasted that the lack of physical keys meant that the user interface was entirely flexible.
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