Hitachi has developed a chip that could be woven into paper money to help identify counterfeits and could also have wide ramifications for identification and surveillance technologies. The chip, called Mew, measures just 0.4mm on a side and stores information such as identification and security codes. Most identity chips are currently several millimeters on a side. Mew includes 128 bits of read-only memory (ROM) and RF wireless circuitry that allows it to transmit over a distance of about 12 inches. If the chip were inserted in money, a reader unit would be able to instantly detect authentic bills.
http://dailynews.yahoo.com/h/cn/20010703/tc/hitachi_in_the_money_with_tiny_chip__1.html
