I've been working on a sensor reactive lighting system for my kites recently. For sake of simplicity and rapid development, the system is currently Arduino based, running 2 panels of 4 superbright RGB LEDs. I just took it out on its first test flight last night.
Video at http://www.vimeo.com/1392439
Pictures at http://www.flickr.com/photos/qdot76367/set...57606246910762/
This is all mounted on a Trick and Track at the moment, because it was just a nice, already fairly heavy, precision kite. The whole system adds around 60g of weight to the kite, making flight experience something like driving a late 80's model volvo (especially in the 6-8mph wind I was getting last night). I can still axel/backflip it, but it's not too happy about the idea.
Now that I at least have proof that it will both fly and look pretty, I'm going to start working on scaling all the circuits down to smaller, surface mount based boards, and redesigning the power supply to be something that's not a 9v battery. I'm also starting to spec out quad line and stack setups.
I'm working on multiple control interfaces for this in parallel with the actual system design. Playing with all sorts of different sensors (ultrasonic rangefinders, which will probably be far too noisy in this environment, photoresistors, accelerometers, etc...), and I have Zigbee boards on order so that I can do radio control and relay (for music based light control, etc...) from the ground and possibly across multiple kites. I'm also working on design ideas for light node mounts, with the possibility of using the sail for color diffusion and blending (which is why I need to buy a silver fox UL soon ).
If anyone has idea ideas they'd like to see implemented, I'm open to suggestions.
Also: I'll be at the Berkeley Festival this weekend with the kite, if anyone is interested in seeing it in action (though it's not all that impressive in the daytime)