Gillette is trialling tags for its razors with Tesco in the UK and Wal-Mart in the USA. Razors are small, relatively high-value items and a favourite target for thieves. But if they lift an entire case of tagged razors, the RFID reader will spot the mass exodus and ring the alarm.

But tag prices will have to fall a long way before tags can be used in mass markets. Today the cheapest tags sell for 50 cents to 80 cents. That may be acceptable for a $200 DVD player, but is still high in the case of many consumer items.

And there are still technology issues to be addressed. RFID readers can’t read tags through steel. So RFID technology can’t be used for canned food, thus puncturing the dream of a RFID reader automatically totting up the bill at the checkout.

And different governments around the world favour different radio frequencies. Whilst most readers can pick up most tags, many frequencies are weak. This means some readers have to be 10-30cm from the tag to read it. That is not good enough for most warehouses.

But Ashton reckons all this can be ironed out: "Perhaps one day the can will be the antenna itself," he suggests.

In any case, Ashton says it is a mistake to become fixated by mass usage. On more expensive products, and in closed supply chains, RFID technology can be applied today.

Our Analysis: It is almost certain that everything will be tagged within 20 years. Small wonder journalists are already enjoying themselves exploring the possibilities for a totalitarian Brave New World in which RFID readers in the street profile all your possessions prior to sending you a very special offer. The big question is how fast the world will move to RFID technology.

But, of course, the really big question is how soon you should start tagging your products.  One answer is to visit the AutoID Center. There you can find a simple questionnaire which, maintains Ashton, can look at your volumes and product price and give you a reasonable assessment of whether it can be RFIDed today.