Daily Mail:

The ground-breaking digital blue box was developed by Apple’s co-founder Steve Wozniak in 1972 and was the inventor’s first printed circuit board.

But the box was actually a hacking device that fooled a phone company’s switchboard by reproducing its specific tones.

As a result, the user was able to get free overseas phone calls in an era when making a long-distance call was hugely expensive.

Click through to the post. Some terrific pics and a video of Steve Jobs telling the blue box story. This is a piece of history I would love to own.