I made a charlie(brown)plexing tree!
If you don't know what charlieplexing is, it is basically making each wire at the end of the matrix map to one and only one LED. This is assuming that all of the other wires are disconnected. The cool thing is, because and LED is a light emitting diode, we can use the same two wires twice and just revise the voltage applied assuming that the LED you have is able to stand that reverse bias voltage level... So this is a cool way to address a bunch of LEDs in a very low voltage way, like shown here.
Here is a graph showing how awesome charlieplexing is:
OK, the graph shows how many pins you would use vs how many LEDs you can control.
I am tired, maybe more later, if not see you next year.