Lots of games have Easter eggs, but rarely does one stay undiscovered for seven years. That's the case for a particularly well-hidden Halo 3 secret, which was just recently outed by some intrepid fans.
The Easter egg was discovered by Team Beyond (via IGN). By holding down both thumbsticks during the loading screen on December 25, the screen pans out to give a wider view of the Halo ring. In very light print on the ring, you can read the words "Happy Birthday Lauren!" You can see it for yourself in the video below.
Bungie itself has slyly acknowledged this Easter egg in the past in its Mail Sack features. One employee said it only happened on a specific day, while in another entry employee Adrian Perez said he was proud of having shown his wife the Easter egg he inserted for her. In both cases, the employees noted that no one had found the secret yet, but now we know. Presumably Lauren had a nice birthday surprise, back in 2007.