This concept idea shows a regular wall socket with an extension cable hidden behind. With the extension cable wound up in the wall the user can simply detach the socket front and pull the socket out further lengthening the amount of cord available.The cord inside is designed to be 1.5 meters in length. To use the cord extension you simply pinch the sides of the socket and drag it out of the wall to the desired length.
When you have finished using the extended cable you give the cord a gentle tug and a spring mechanism then pulls the cable back in to the wall for storage. It's a nifty idea although I am not sure how easy it is to store 1.5 meters of cable within the socket of the wall.