Its a 'must watch' isn't it. What they did with the seaweed (an Orcadian suggestion) to move the stone was fascinating. And I applaud the cameraman who filmed Andy Torbet climbing up the sea stack.
I went to Orkney at midsummer in 2009, the day started off with a bitterly cold wind and turned into a wonderful warm summer's day - quite rare judging by the wind burnt look of everyone in the programme. Later that summer, back home - I went on a guided walk around Avebury organised by the NT. The walk was led by an archaeologist who had previously lived and worked on Orkney (if I recall correctly, her name was Matilda) she was the first person to point out to me that the Ring of Brodgar was the same dimension as one of the inner circles at Avebury and that Avebury seemed to mirror the Ring of Brodgar but on a much larger scale. Even back then there was a clear school of thought that it all started in Orkney and cascaded south.