There's a post credit scene that goes back to the TV studio where the one of the host tries to pick out a challenged person just by looking at them from the back.
In the opening scene of the episode an image of Jon Pertwee can be seen in the newspaper along with the words "free Doctor Who DVD".
Daniel Radcliffe and Warwick Davis starred together in the Harry Potter series as Harry Potter and Professor Flitwick/Griphook respectively.