As the ability to be able to share, visually, any particular moment of my life becomes more important to how I define myself (it's sad, but it's true), it seems extremely archaic that you can't take photos in art galleries. How will my crappy phone picture ever recreate the experience of standing infront (or amongst) an art work and drinking it in?
I understand that flash photography ruins oil paintings, but I don't think that applies to modern art. And in my experience, the American modern art galleries have a much more relaxed attitude to photography, which leads me to guess that the no-photo rule is rooted in tradition (and fear of piracy?).