At this stage of the proceedings, Foxconn must be churning a triillion iPhone 5 units per second, getting ready for the September 12 launch. Nor surprisingly, it seems someone managed to smuggle one out of a factory in Jincheng, China. Not just parts, but an entire unit.
The phone seems complete and booting. It stops just before showing the unlock screen with this error:
This device is not registered as part of the iPhone Developer Program. If you are a member of the program, please register your device in the @@url@@.
After all the leaks it seems highly unlikely that this is any kind of prank or fake—unless Apple has played the biggest deception operation since the Allies made the Nazis believe that Operation Overlord was happening in another place.