Here is a cool invention that enables your dog to let you know when it is ready to come inside. The Doggie Doorbell helps you train your dog properly to avoid scratches all over your door. It has a built-in treat holder, so you can train your dog to ring the doorbell. You can use this tool for potty training as well.
If you get the twin-pack, you can install a transmitter button on each side of the door, enabling your dog to let you know when it needs to go out or come back in. The device has a range of 250 feet and 36 selectable tunes. You also get volume control. The Doggie Bell is suitable for indoor / outdoor use. What do you think? Are you impressed?