On the second disc of the Double Disc edition of the DVD there is a Special Features menu listing about eight programs. If you press left from any of these the cursor moves onto a hidden box, giving you about eight more features to watch.
Collateral (2004) - 1 easter egg
Directed by Michael Mann, starring Jada Pinkett Smith, Jamie Foxx, Tom Cruise
Easter eggs are hidden bits on DVDs which aren't advertised on the cover, but if you know where to look can provide all sorts of fun extras.
On the second disc of the Double Disc edition of the DVD there is a Special Features menu listing about eight programs. If you press left from any of these the cursor moves onto a hidden box, giving you about eight more features to watch.