Sunglasses that serve an even more useful purpose than protecting the eyes of the blind. They can help them detect objects in front of them.

There are a lot of Arduino-based metal detectors using various technologies. This is one of them that uses direct frequency measurement.

Speedometer that uses a GPS for speed sensing and an RGB LED to indicate speed to the user. Also features a blinking white light.

Move your hand around - lights ON. Move hands over that again - lights OFF. Cool, right?

A pair of talking smart glass, intended to help the visually impaired.