Pillow Fight!
While waiting for my BART train in Berkeley I saw two people getting off the train from San Francisco, each carrying a pillow. No sleeping bags or suitcases, just pillows. It's not the strangest thing I have seen on the BART, but it did make me stop for a moment and wonder "why?".
Well DUH! Obviously they must have just come from a massive PILLOW FIGHT in San Francisco!
It was "organized" entirely over the internet, so naturally the event is already well documented on Flickr.
Let the feathers fly!