http://www.bbc.co.uk/iplayer/episode/b00yd7f4/Hidden_Histories_Series_3_Episode_3/

For anyone who doesn't live in Wales - this episode of Hidden Histories is worth catching online. About 22 minutes in, it features the burial chamber of Barclodiad-y-Gawres, with the use of 3D laser scanning and digital photography to record the rock art for future reference. George Nash from Bristol University makes an appearance.