If you're in London with an hour or two to spare before 13 September, I'd highly recommend a visit to the Science Museum to see REVELATIONS Experiments in Photography, which has been on my list all summer but which I only managed to squeeze in last week.  The exhibition includes rarely seen works from the mid-19th Century by pioneers like William Henry Fox Talbot and Edward Muybridge as well as pieces by contemporary artists who aspire to match what was being created 150 years ago.  Sometimes we do have to look back to see if we're moving in the right direction.