MORE than eight years ago I managed to get my hands on one of the first miniature digital cameras, about the size of a shirt button. I mounted it in a badge that I wore at public lectures for the sole purpose of a surprise demonstration. When I reached the end of my lecture, which featured the miniaturisation of technology, someone always asked a question. I would respond by walking into the audience to get as close to the questioner as I could, and then activate the hidden camera with a concealed switch. The questioner would suddenly be projected on to the screen behind me, and as I then moved about the audience would try to guess where the camera was located. Often it would take a few people some time to figure out I was the cameraman.

Since that time miniature cameras have become even more miniaturised, more available, less power-hungry and have far better definition and sensitivity. They are commonly used in banks, shops, streets, parks and public buildings, and some are worn by the police and emergency services. Cameras are now everywhere, present little threat to our privacy, enhance our security, and result in few surprises.

More recently I was at a conference where Paul McCready - the gossamer condor designer - walked on to the stage with a model aeroplane with a wingspan of only 70cm. Solar cells provide the power for two electric motors, a miniature camera and radio system. The house lights were turned up and the aircraft came alive. He flew this almost silent aircraft around the auditorium, powered only by the house lights, at speeds up to 50km/h, while at the same time videoing the audience.

He then pulled a 15cm version from his coat and repeated the demonstration minus the miniature camera, which was too heavy for this frame. Finally came an ornocopter, which looked like an insect, and weighed only one gram. This was a rubber band powered flying machine of 10cm wing span that flew like a fly, with flapping wings. It took off, flew to the top of the auditorium, and then disappeared through a vent. This was an amazing amalgam of new technologies, and presented solutions looking for problems.

I was immediately prompted to ask the most obvious question: what could this technology be used for and what are the implications? Well, military drones for gun control, logistic observation, arms and border control, and even low-cost missiles are obvious applications. In the civil arena they would clearly make ideal observation and control platforms for congested roads, fishery protection, or scanning accident and disaster sites.

But how about sporting events? Low-noise, low-visibility units could fly above an arena to give us a bird's eye view. And perhaps we could even afford individual control to a limited audience.

Perhaps the most radical step with this technology will be successively miniaturised flying platforms with sensors and intelligence. Flying robots have arrived, and soon we will all be able to afford eyes and ears in the air anywhere. Now these really will have an impact on privacy, and I suspect we are going to need a new raft of regulation and control.

Peter Cochrane holds the Collier Chair for the Public Understanding of Science & Technology at the University of Bristol. His home page is:
http://cochrane.org.uk