A new thinner-than-paper-thin RFID (radio frequency identification) chip has been developed by Hitachi Ltd. "Ten or more times thinner than a sheet of paper" (shouldn't that be 1/10 the thickness?), it is 0.15mm x 0.15mm x 0.01mm. Paper is .08mm-.1mm thick so the new chip could actually be used as a watermark.Applications could easily include enhanced document security. The chip could be embedded in optical media (would RFID interfere w/ electronic media?) such as DVD, CD, etc. What about embedding in clothing, jewelry and watches, etc. Making the tracker inconspicuous raises the possibilities.