You could run a chain or something from one side of the room to the other, and screw eye bolts into the top plates or studs in the walls, up as high as you can go. If you have moldings running around the wall to ceiling area, they usually are only air nailed in, and would help to cover up the holes back up if you temporarily remove them. OR, just drill right through them, than fill the holes back into them later with wood putty, etc.