When Brennan and Dale are in their room, showing each other their night vision goggles and autographed sword, the camera pans around while the characters are walking, and a Hugalo's Pizza car light is on top of the chest of drawers in the room. Will Ferrell's character worked for Hugalo's Pizza in Talladega Nights: The Ballad of Ricky Bobby (2006), after he lost his job as a race car driver.
In the commentary, Adam McKay said that they originally went to Catalina Island for location shots, and discovered that he didn't really like it. Instead, they shot on the coast. Catalina Island appears in several shots, and McKay chose not to have it digitally edited out, as a joke.
The name of the high school, in which Brennan (Will Ferrell) performs during the talent show, and gets made fun of by Derek (Adam Scott), is Great Valley High School, which is the name of the High School Adam McKay attended.
During Dale's job interview, Ken Jeong says he knows of a catering company that is looking for people. This is a reference to Ken Jeong's character (Alan Duck) in the series Party Down (2009), who owns Party Down Catering. Adam Scott is also in Party Down (2009), as a caterer.
Brennan says he smoked pot with Johnny Hopkins and Sloan Kettering. There is a Memorial Sloan-Kettering Cancer Center in New York City, which is also mentioned in the lyrics to the opening song "A-Punk" by the New York City band Vampire Weekend, and although it's not exactly called "Johnny", the famous Johns Hopkins hospital is in Baltimore, Maryland.