Something kinda neat I ran across the other day:
The russian guy who built it is using it for his own custom 10-channel compositions, I think. But - what if you hooked up something like this for 5.1 or 7.1 sound? You could put a "subwoofer" in the center. And then you could wear it on your head like Doc Brown in Back to the Future:
Naw, just kidding about the wearing it on your head part. But - if it was raining and you were using an umbrella anyway? Or maybe it could catch on as an alternative to those stupid ear-buds everyone wears these days. I can see needing some kind of flexible, easy-to-see 'guard' around the circumference so random passers-by don't poke out their eyes on the tines.
Also, it occurs to me: what if you made a large (yet light-weight) version of this, that had a radius of 10, 15, or 20 feet? You could set it up while camping, or at the beach, maybe inside of a tent - either just for music or if you had a 15" or 17" notebook computer, you could have a group 2 or 6 people sit together and, basically, it's a portable Home Theater system?
BTW, http://vtol.cc/ has a lot of fascinating music/tech/art stuff on it.