In case you didn't know, you can unlock a free "Reach Beta Tester" hoodie for your XBL Avatar by playing the Reach Beta. Simply play the beta at least once (ever) then go into Halo Waypoint, select "Career", and have it scan your game progress. When it's done, you should receive the notification that the award has been unlocked.
My avatar is wearing it now if you wanna take a look. (Image attached.)