Major Nelson explains how users can change the background image on the 360 blade to a hi-def image from the water balloon fight that the Xbox team hosted in Australia. I never knew that I could change the background image, that's rather cool!
Doctored instructions from MN's blog are below:
Once you sign in, go to the Media Blade, then to Pictures. Go to Portable Device (such as a USB memory stick) scroll to find the photo (you'll see a thumbnail) and when you have the photo highlighted, press X.
Very good to know! I'm surprised I didn't notice this when I read the 360 manual. Perhaps I read the wrong one 🙂