Rolf Hut made an awesome Anti-Hug Hat, or personal space protector, for Burning Man this year.
The Dutch scientist wanted to explore working with Teensys and APA102 LEDs – and wanted a way to try to avoid the typical American hug at Burning Man, so he came up with the Anti-Hug Hat. The hat has acoustic distance sensors around it an when an object (like a person) gets too close, the ring of LEDs around the hat change from green to orange to red.