Easter egg: In the language selection screen, while playing the DVD on your computer, run your mouse over to the left side of the title saying Language Selection. The Average Joe's face will then appear on the left. Click on it, and the movie will start with an alternative commentary by the director, Ben Stiller, and Vince Vaughn.
Easter egg: On the region 2 DVD clicking the Purple Cobra logo on the Special Features Menu will play an alternative commentary featuring Rawson Marshall Thurber, Vince Vaughn and Ben Stiller.
Easter egg: Go to the "special features" section and at the bottom towards the right is the Purple Cobras logo. Click on it and an overweight White Goodman appears, telling you the Easter Egg is to hit enter every time his character snaps his fingers during the movie. (00:21:40 - 01:02:15)
Answer: There were many celebrity cameos throughout the film. It's just kind of strange that Chuck Norris would do this.