The David Tennant Treat 4 Today is a clip of David Tennant, John Barrowman and Freema Agyeman filming The Last Of The Time Lords in Cardiff.
This was the clip when Captain Jack told The Doctor that he had been called The Face Of Boe. Near the beginning of this clip, the photographer pans to show how many people were watching filming that day and yet nobody picked it up!
My favourite part of this clip occurs at 17 seconds. The dresser is brushing down David (which is part of her job) and yet he takes the time to thank her.