Hand Radar is an idea we came up with, during first edition of Travel To The Cloud Hackathon in Gdańsk.
It's an electronic device based on simple Arduino Uno board, ultrasonic distance meter and vibration motor. It works quite simple - the closer is the obstacle you're pointing at - the more intensive and frequent are vibrations coming from device. As a prototype, it's mounted on a palm, and signal strength is represented also by blinking light and beeping buzzer.
Future versions could use laser distance meter that is much smaller, and thus entire device could be mounted on just one finger.
We believe such device could turn quite helpful for people who are visually impaired, and become useful addition (or extension) to the regular white cane.