Telephone

In 1945, the US FCC chairman predicted handheld wireless telephones would arrive soon. Instead, radio spectrum went to television, delaying mobile communication by decades. AT&T forecast 900,000 US mobile users by 2000; the actual figure was 109 million.

In 1957, a blind boy named Joe Engressia with perfect pitch discovered that whistling a 2600Hz tone into a telephone could manipulate the phone system. This became known as 'phreaking.' Among the next generation it inspired were Apple co-founders Steve Jobs and Steve Wozniak.