Very cool and original indeed. This stool made of 100% cork and named Sway Stoll by its makers dmfd, swivels when you sit on it.

More details from the designers:

These stools are made completely from cork that originates as the waste material from the bottle stopper industry. The central column of the stool, located directly under the spine of the user, is flexible, solid cork while the rest is perforated. The result is a seat that flexes and pivots under the weight of the user, responding to the slightest body movement. The user’s muscles remain slightly engaged to maintain balance, improving posture and circulation. Many have reported this to be a perfect seat for working at a desk or computer, enabling the user to move and rock while working and thinking. - dmfd