The Halo 2 videogame had an elaborate Alternate Reality Game (ARG) called I love bees that tied in with the launch of the game. It involved real world people getting emails, text messages, phone calls, etc, from in-game entities, artificial intelligences, and other characters.
It looks like those crazy Bungie guys are at it again, but this time for Halo 3.
Click on the image or go to http://halo3.com/comic/ to check it out. I accidentally found the clue that lead me to more parts of the game.