Written on a rainy summer afternoon just four miles from my home in a local café with a free wi-fi service.
At a recent conference I was describing how mobile devices would become even more indispensable if fitted with an accelerometer and other sensors, when I was challenged.
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So I described how a mobile phone could be transformed into a pointing device. To dispel the evident scepticism, I recounted an experience of about two years ago when I saw the first mobile phone combining GSM with GPS, a compass, and an accelerometer.
When I stood in the street, the phone knew where I was and in which direction it was pointing. When flicked towards a building like the White House or the Washington Monument, it said so.
At the time I thought this could be the start of a development thread that could well be profound - and I still believe it is.
The ageing population in the West is going to need a lot of electronic support, and I suppose that will soon include me too.
So how about wearing a mobile phone that records your every movement? The behaviours recorded would represent a reasonably regular daily pattern.
Out of bed at 7am, walk to the kitchen for breakfast, read the newspaper, and go for a constitutional at 9am, visit a coffee shop at 10.15am, and so on through the day. I'm sure you get the idea.
What happens if you are not up and about as usual, and especially if you are not mobile in any way? Your alarm sounds.
If you don't respond, you get a phone call on your mobile, which is followed by one on your fixed line should you remain unresponsive. Ultimately a visit by a relative, neighbour or residential warden could be triggered.
Seems to me a really cheap solution that we could all easily afford. Should we wander off and get lost, or God forbid, have an accident or stroke, the alarm would be raised and we would be located quickly.
I would just ask the sceptics to mull this over and then try to imagine the additional implications for every profession and every industry.
Lone workers and people at physical risk spring to mind but then again so does the games industry. A mobile Wii would be really something, and so would air pressure and pollution measurements.
Peter Cochrane is an engineer, scientist, entrepreneur, futurist and consultant. He is the former CTO and head of research at BT, with a career in telecoms and IT spanning more than 40 years.