Gus asks for some Turkish Delight, which is an in-joke that the actor played the White Witch's Dwarf in the Chronicles of Narnia.
Danny is recording an audiobook of Jane Austen's "Pride and Prejudice".
Danny's autobiography cover is in a similar style to "The Guv'nor", Lenny McLean's autobiography.
Tamsin Greig and Michael Walter both appear in Green Wing.
There is a Dilbert joke that is similar to the boardroom diagram joke. Dilbert shows a meeting a complicated diagram out of nowhere and says "Any questions?" and is immediately asked for a copy of the presentation. Scott Adams has himself commented on the phenomenon of humorists unintentionally arriving at the same joke.