The XNA Game Studio has a component called the XNA Device Center. You can configure your X-boxes in this tool, if you have more than one, and switch which one is active. You can also right-click on a connected X-box and choose "Screen Capture."
However, I think something broke in the latest update (3.1). What do you think? :-)
Also filed on Connect.
I can't make up my mind whether this is a bit-reverse view, or an RGB view of the depth buffer... although the floor is a plane, and should be more homogenous than noisy if it was pure depth bits...