Bilibot an open source robotics platform utilizing the Kinect as main sensor.
For 380 Euro you can get skiing goggles with a integrated Headup Display showing speed, height, distance from your starting point, position temperature and time.
The goggles have an integrated GPS-receiver, accelerometer, temperature and pressure sensor. Also they are recording position data that can later be downloaded to a PC via USB for display.
The Headup Display is also available separately for integration into other goggles for 304 Euro. But not right now both offers are sold out.
an article at display-magazin.net
a paper on VRDs: Funktionsweise und Einsatzmöglichkeiten von Virtual Retinal Displays
Some use cases for pico projectors.
The German Company Festo created a series of robotic flying and swimming animals. Really fascinating.