The Decelerator Helmet by German artist Lorenz Pottahast is a very intriguing concept. From the outside, it looks like a reflective bubble with a display on it. Inside the helmet, it displays a real-time video signal in slow motion. The helmet features a forward-facing camera that feeds the signal to a small computer embedded in the helmet, which is slowed down and displayed to a head-mounted display inside the helmet. After a while, user can speed up the video signal to catch up to the present.
This helmet breaks the connection between the user and his time, providing a unique experience of inconstant time. Too bad it's only an art project. I'd love to buy one and try driving with it on. Check out the helmet in action in the above video.