From the "Special Features" menu, select "Filmographies". Next, select "Cast". Highlight Tom Sizemore's entry and press left to highlight a helmet. Press enter to view an outtake with Sizemore.
From Disc One's main menu, select "Special Features". Once in, hit "Commentaries". Highlight the "Index" option for the author/screenwriter commentary and press right. Hit enter to view "Ken Nolan's DVD Commentary Do's and Don't's", a fascinating read about creating a superior commentary.
All easter eggs were generously submitted by phat_tonyca