BBC 4 Series: "The Genius of Photography"

A fantastic BBC4 documentary series, "The Genius of Photography," is currently available on YouTube.  It's not hosted on an official BBC YouTube page, so who knows how long this series may be available.  (It's also one of the growing number of items available in higher quality--go to the originating page, and click the "Watch in High Quality" option beneath the screen, lower-right).

There are several Episodes online, with each episode broken down into parts.  The clip below kicks off with Martin Parr and John Gossage on a road trip.