Special Move
It lets you enable or disable the auto-extraction feature of disc-images.
"Special Move" is a drag'n'drop application that let's you enable or disable the auto-extraction feature of disc-images (".dmg" files) that was silently introduced with MacOS X v10.2.
About "auto-extraction": If you enable auto-extraction for a particular disc-image, "Disk Copy" won't mount this disc-image, instead it will copy the content of the disc-image to the folder that holds the disc-image.