The final Easter Egg hidden within Bungie's Master Chief-centric trilogy capper for Xbox 360 has been discovered.
The folks over at Teambeyond.net have managed to figure out that if you press and hold down both thumbsticks during Halo 3's loading screen on December 25th, you'll get a pulled-back view of the Halo ring, and on its surface you'll find the message: "Happy Birthday Lauren!"
Look closely or you might miss it.
Halo 3 launched back on September 25th of 2007. It's amazing that Bungie has managed to keep this secret hidden for so long!