Micah Elizabeth Scott (@scanlime) came to talk about Fadecandy, a really neat way to control smart LEDs (NeoPixel, AdaFruit's term for the WS2812). The conversation ranged from beautiful LED control algorithms and open source embedded projects to triangle tessellations, art, and identity.
AdaFruit has a great intro to Fadecandy.
Fadecandy is open source hardware and software, see the repository.
Micah's blog is a combo of art and technology.
Burning Man's Ardent Mobile Cloud (also a lovely still pic).
Elecia also mentioned Deep Darc's hack of the GE Color Effects lights.