A hole for the camera is present, so we do not lose that function of the phone. This is also where the clip mechanism is located, used to open and close the OtterBox.
One thing I did not notice at first (nor did I find any mention of in the instruction manual); if you look closely in the second picture above, notice the brass screw hole. With the latch in the closed position, it would seem that you could add a screw here for added protection, ensuring that the clip mechanism would not accidentally come unlatched.
Anyway, now that we have the case open, let's take a quick peek inside then see how the Treo fits...






