On the Main Menu, if you choose the folowing Character, Shirt, and Weapon, you will unlock the hidden version on the DVD. Choose Hutch, the blue & white shirt, the shotgun and then press Activate. This will change to the Hidden Menu and features.
Actually all three characters open different menus if you take the time to mess with them. When you get to the menus you can click on the symbol to the left of the selections and each characters menu will give you a different word. The words are Reflection, Rose, and Elizabeth.
After obtaining the three secret words, elizabeth, reflection, and rose from the "create your own character" extra, go the the movie's official website. Click on the "create a character" link. In the lower right corner of the popup is a space to enter the passwords in order to create your very own morbid email signature.
All easter eggs were generously submitted by SirDonk