The David Tennant Treat 4 Today is part of David Tennant's Video Diary. This clip is from the Weakest Link Doctor Who Special.
When David filmed this there was talk that he was concerned about getting back to Cardiff afterwards for Doctor Who filming the next day as the recording was taking a log time.
However he seems quite competitive in the filming so there's some doubt about that!
Apologies if the video does not play in your country.