This morning’s Observer column.

The computer mouse was a key element in the icon-based interface that we now take for granted, and it was a great success in its day (though Engelbart did not make a cent from it). Last week, for example, Logitech, a leading computer accessories manufacturer, announced that it had shipped its billionth mouse. ‘It’s rare in human history that a billionth of anything has been shipped by one company,’ Logitech’s general manager Rory Dooley told the BBC. ‘Look at any other industry and it has never happened.’

Up to a point, Mr Dooley. What about paperclips, Bic pens and Faber-Castell pencils, to name just three? But it may be that the mouse has had its day. It’s not much use with an iPhone, and no good at all when it comes to controlling a video wall. The industry is moving towards new interfaces controlled by touch, gestures, voice and maybe even eye movements. In 40 years, Logitech’s latest gesture-based MX Air Mouse will doubtless look as quaint as Engelbart’s wood-encased wheel-mouse does today.

Not that he will give a damn. Mr Engelbart has always viewed technology as a means to an end, not an end in itself…