Easter egg: On disc four of series 3, go into the scene selection, go to the last page, highlight "keep looking" and press "up." You know have the whole easter egg that was part of the story.
Visible crew/equipment: During the warehouse battle, around when the Doctor tells Donna, "Hold on, I'm coming", the film crew can be seen reflected in a door at the right of screen. (00:28:20)
The Doctor: I'm not... I'm not... I'm not from Mars!
Trivia: In "Human Nature", when John Smith (The Doctor's human identity) is talking about his parents, he says their names are Sydney and Verity. Sydney Newman was the creator of Doctor Who and Verity Lambert was the first producer. (00:30:00)
Last of the Time Lords (3) - S3-E13
Question: Why does The Master fear The Doctor forgiving him? What's he forgiving The Master for exactly?
Chosen answer: The Master knows that deep down, he deserves death for the crimes that he's committed throughout his life, and since he regards The Doctor as his arch-foe, he expects it to be at his hands. The fact that The Doctor is still willing to forgive him after everything the Master's put him through hurts him more deeply than death would.
Captain Defenestrator