Easter egg: On the first page of the "special features" menu, you will notice a blank space in the middle between "more" and "main menu" on the very bottom of the page. If you got to the main menu button and then go once to the left, a series of numbers like the ones Ben Kingsley draws in the movie will appear where that blank space is. If you select it, it is a short interview with a Taoist master about the "third eye" principle.
Easter egg: On the 2nd disc, if you go to dissection then hit the down arrow then the right arrow, it will tell you the story of Billy the puppet.
Easter egg: On the normal version of the DVD, in the subtitles section, there is something called "The Zomb-O-Meter Track." Select this, and have a whole heap of extra trivia appear as subtitles, such as music credits, storyline pieces and other good stuff.
Easter egg: In the 2 disc special edition, on the pre-production menu, towards the bottom, if you click right, you'll highlight a face-hugger. Click it to see an interesting video by Tom Woodruff Jr., the lead alien.