There is also a hidden DVD-ROM option on DISC TWO. On the main menu, go to the screen that offers the trailers & documentaries options. Scroll left as far as you can, then scroll down, and a DVD-ROM option will appear.
DISC TWO - click on "Main Menu" and select the "Audio" option (the speaker at the top left). On the right speaker, there is a face grabber from Aliens. Clicking on this creature brings up the short teaser
On DISC TWO, go to the option for the documentaries. Choose the 60 minute one, and then get to the chapter list. Scroll down through the chapters (this takes a while) and on the last one, stop. A facehugger will appear at the top of the screen. Scroll left and highlight the facehugger, then select the trailer.
DISC TWO. Go into More "Special Features", the "Personnel Lockers". The last page has an "alien cocoon" at the right side of the screen. clicking it will show another Aliens trailer.
DISC TWO - in the same spot as the face-grabber, click on "Main Menu" and select the "Audio" option. On the left speaker, there is a "hydrophone test" that plays a 12 second sound feature.
On DISK TWO go to the "Main Menu". Select the Subtitles option. The TV screen on the menu will flicker and then flash the message "Transmission lost..". Press your Left button and you'll highlight a facehugger. Select it to go to a TV commercial for Aliens.
On DISK TWO, the "Imaging Station". Highlight the "Pseudopod Multi-Angle" feature. Then press your Left button once. A small facehugger will be highlighted on the left side of the TV set (it's a little hard to see). Select that for yet another Aliens trailer.
Theatrical trailers for Strange Days, True Lies and Aliens - DISC TWO - click on More and Trailers (far left). The posters for these movies are mostly covered by The Abyss trailers that are available but navigating around the posters should let you get at these previews.
Oh, one other thing -- there happens to be a SECOND trailer (a different one) for True Lies, also on the 2nd Abyss disc. You have to go to "The Abyss In Depth: Mission Components". Once at the first page, after leaving the Sub Bay, you then have the option of pressing down to go further into the abyss, OR pressing up to go to the surface (this option may not be self-evident; the yellow arrows only show up when the correct button has been pushed!). Once at the surface, we see a nice seaside landscape, but at the very top of the page is a tiny airplane. Pressing your Up button highlights the plane, and then pressing 'enter' takes you to the alternate True Lies trailer. Try it yourself!
Now, most of the trailers CAN indeed be found via this method, (the True Lies link is actually just a small box at the bottom of the page). However, the one for Strange Days is a bit trickier. It isn't even available at the trailers area at all. You have to access the "Imaging Station" first (yes, still on the 2nd disc), then highlight the "Image Gallery Menus" option. Press your Down button. The TV monitor on that same page will change to show the following cryptic message -- "You know you want it and I can give it to you. I'm the magic man, the Santa Claus of the Subconscious". Then when you press your Enter button, only then are you taken to theatrical trailer in question (basically a close-up of Ralph Fiennes talking directly to the audience; during his monologue he repeats the lines mentioned above).
All easter eggs were generously submitted by SirDonk