Christmas is coming, so more embedded projects tend to be related to something nice. Chris Lomont have been building a 4×4x4 RGB 3D LED Cube that makes nice effects.

Cube is light effects are generated by PIC18F4620 microcontroller, which gives enough calculating power to make smooth effects. Also you can check out prototype of 8×8x8 LED cube , which seems to need much more processing power than single microcontroller can produce. 4X4×4 Led cube is pretty complete project and it is possible to buy a kit. Anyway I have enjoyed reading the description of development process with lots of illustrations and explanations. Have fun.