I'm immediately adding this one to my Personal Favorites. Touch Echo is a stunningly simple and effective outdoor exhibit in Dresden, Germany. It uses bone conduction technology (sound transfered through the bones to vibrate the ear drum, allowing you to hear sounds that have no noise) to listen to the sounds of the 13th February 1945 air raid that happened at that location. Visitors to the site put their elbows on the railing and cup their hands over their ears to hear the raid. I think this is a brilliant use of bone conduction. I particularly like the respectful, meditative pose that it forces listeners to adopt which adds to the experience and the message it has to others watching. This concept also has a sense of magic to it which I really like. The idea of a specific pose transporting you to another place and time, while others around you are unaware, is quite amazing.