People into baseball cap like me could be interested into cap-mounted display such as the one designed by Lars Johansson and Niklas Andersson. One of their MSc student (Fredrik Nilbrink) designed a prototype:

This project’s purpose was to investigate the truck operators needs and to see how modern digital technology can help to reduce the paper work and increase the productivity and make the operator’s working situation better.

Concept I: Cap Mounted Display A monocular display unit is mounted on an ordinary cap. The unit also contains microphone, earphones, camera and Bluetooth units. The device is voice activated. (...) He [Fredrik]] took apart a pair of Sony Glasstron VGA-glasses to get the monocular Head Up Display we wanted for this project. On top of the cap a web camera was mounted.

Why do I blog this? a cool hack here but I am wondering about its usage in a real-world setting.