Just think. An enormous pillow fight in the centre of London... and us there, with our cameras. How is this not the perfect way to spend an afternoon? (There are only two rules, and the first one is "don't hit anyone holding a camera").
We'll meet nearby beforehand, and aim to arrive shortly in Trafalgar Square before it starts, so that we can capture some of the preparation scenes as well as the complete mayhem which will follow.
The pillow fight will last for as long as people have stamina, and the same applies to us too; we'll decamp to the Chandos (heavenly sofas upstairs!) once we've had enough.
Further details are on http://www.timeout.com/london/things-to-do/international-pillow-fight-day, and photos of last year's can be found on http://now-here-this.timeout.com/2013/04/08/in-pictures-the-great-trafalgar-square-pillow-fight-of-2013/
Obviously, tripods won't last too long, and although zoom lenses will be nice, you will get better results with a wider prime lens. Look forward to seeing you there!
Please pay in cash on the day, and my number, if you need it, is 07955 861414.