Spot the Pineapple: a glass pineapple can be seen sitting on a table in Desperaux's hotel room.
Shawn's line, "Where does he get those wonderful toys?" about Despereaux's Batman-like grappling gun is a callback to Batman (1989) when Jack Nicholson's Joker says the same thing.
The hotel was called the "Gordon Mark Hotel" after Series Producer Gordon Mark.
At one point Shawn tells Despereaux, "It was true love". Despereaux is played by Cary Elwes who was in the Princess Bride where "true love" is one of the repeated lines.
The Gordon Mark Hotel, which is where Shawn and Gus stay (paid for by Despereaux), is the same hotel at which Despereaux stays during "Extradition: British Columbia."