To hang something on the wall without hammering a new nail, using the nail just above.
Print it, then pass a wire (for example a fishing line, that is almost invisible) through the hole.
Tie the wire with a knot, then hang the wire onto the existing nail.
The hook is ready to host your picture.
(Warning: the hook is for about Ã¸12mm diameter holes. I used it to hang a calendar).