A few months ago Charles Buckingham told me about a crowd participatory composition idea he had where every person in a large crowd would have a smart phone that made sound which they could control, to some extent, that combined would form a work of music. After we together made several iterations on the idea: reinterpretations, misinterpretations, experimentation, research, etc. the project became a composition idea for a crowd participatory experiment using home made mylar balloons making buzzing tones and clicking sounds with pizeo transducers, lit up with RGB LEDs and finally popped with model rocket igniters and gun powder.
I go into a lot more detail here: http://blog.x37v.info/2012/10/24/balloons-and-electronics