Tobias Floery built this RGB pixel clock and wrote a detailed explanation describing the build.
These RGB Pixels look like they are fun to work with since they are so versatile. Tobias Floery is having some fun building an RGB Pixel Clock using a string of them. You can see the 3 parts of the project linked to below. Tobias is using a real time clock connected to an Arduino to keep accurate time, he found a good library for controlling the LED Pixels and to mount it he had a custom laser cut mounting plate made. Everything is available on his site if you are interested in making your own version.
Via Hacked Gadgets.