Dave Clausen of NYCResistor built this very sweet cylinder display using 95 RGB LEDs & ATmega168 microcontroller -
The LEDs are individually addressable, and when you power it on, the software cycles through a series of animations, e.g. various moving rainbowy patterns, “rain”, “fireworks”, and so on. It doesn’t serve much of a purpose but it is kind of cool to look at. The hardware and software are open source, so feel free to use/copy/extend whatever you find here (subject to the CC/GPL license terms).
Well done! Head over to Dave’s site for thorough documentation and source – LED Cylinder