This is a really cool device called a C-Loop from C-SLR, that attaches to the threaded tripod mount on your camera. You then attach your camera strap to the C-Loop and your camera hangs securely upside down. I gotta get one of these.
From the Custom SLR Website for C-Loop
In case there’s a question if the C-Loop is strong enough, you can pull a truck with it:
Or use it as a swing.. WTF??
If you buy one of these… Let em know you saw it here first!