Ambient orbs can be used to display all sorts of information, such as new email or voicemail, the weather forecast, and a number of other items. This one is based on an ATmega8 and can be controlled via serial communication. Includes a simple python script for controlling the color of the orb.
via Embedded Projects

MAKE presents: The LED from make magazine on Vimeo.
Interesting mini-documentary on the history and workings of the LED.
MAKE Presents: The LED