The cross-marketing campaign for Mass Effect 3 is a universe unto itself, spanning action figures, books, and more. Here's another way for you to get virtual gear from the Mass Effect franchise: Facebook.
Mass Effect 3 Mission Command on Facebook will let you spam your friends in various "missions" that will help you unlock Xbox Live Avatar items, add-ons, and more. According to a promotional invite to the program, "your decisions will determine the rewards." The more you interact with the app, the more chances you'll have to earn a "custom Paragon or Renegade Xbox 360 with Kinect."
The first "mission" will have you signing up for the Facebook app. According to the site, if the promotion gets "enough recruits," everyone will be able to receive the Normandy prop for their Xbox Live Avatar.
Future "missions" may involve a bit more creativity. For example, next week's challenge will have members submitting a "pick up" or "rejection" line to Liara for a chance to win early access to the Mass Effect 3 demo. A future mission will have you creating a video recreating moves from the game for a chance to win a Mass Effect 3 customized Xbox 360 system with Kinect.
For more info, check out the game's official rules.