I know I bang on a bit about RFID -- radio frequency identification -- and what it all means. It's becoming almost as much a personal obsession as ADSL was for me in the mid-90s. You'll have to bear with me, I'm afraid: you know what nerds are like once they get hyper-focussed.
RFID is a very simple idea -- a circuit receives a coded radio signal and responds by transmitting unique identifying data saying: "This is who I am." Optionally it can send a lot more data alongside, but knowing the machines can find you wherever you are is quite enough to be getting on with.
The current state-of-the-art is quite bulky and complex; you need a chip, battery, aerial and packaging, and that's not going to become ubiquitous. But a paper at MIT's Auto-ID is truly chilling in its implications: it shows how you can cram the RFID functionality into a sliver of silicon the size of a full stop, and how to make the whole thing for around five cents. Battery? Just store the energy from the received signal and use that. Next step is the one-cent version: that's not easy, but I dare say the current work in plastic semiconductors you can print onto surfaces with inkjets will have some role to play.
At one cent, MIT says, RFID will become more common than barcodes. Imagine a world where everything that's made -- and that includes the cheapest stick of gum just as much as expensive stuff -- can be tracked remotely by ubiquitous, near-invisible motes. With a soundless explosion of dust, the Web will expand into the real world -- and what happens then is anyone's guess.
But it'll be a very, very different world, and it'll be here before 2010. More as I get it.