RFID
Controversial RFID technology identifies products according to a radio frequency signature. It is so small and cheap it may even be embedded into currency.
RFID tags are very small chips containing a tiny antennae, and can be fixed to physical items. A number of major retailers are interested in using them as a high-tech replacement for barcodes, as they offer the possibility of improved stock control -- allowing a company to automatically count how many items it has in inventory, and even knowing exactly who is buying what.
There are potential benefits to consumers; but potential risks to privacy. It may be harder to get RFID data than to swipe the barcode.
See w:RFID
http://www.thoughtcrimenews.com/rfid.htm
Money plans: http://news.zdnet.co.uk/hardware/chips/0,39020354,2090580,00.htm
"Civil liberties groups demand halt to RFID" http://news.zdnet.co.uk/hardware/emergingtech/0,39020357,39118035,00.htm