Inventory Spoofing: An Interesting RFID Exploit

According to
http://www.bof.nl/nieuwsbrief/nieuwsbrief_2006_16.html (in Dutch), Vrije Universiteit in Amsterdam, The Netherlands, has developed a prototype of a device capable of:

• Detecting all RFID chips and scanners in its neighborhood
• Keeping an inventory of all RFID chips you carry on your person, and alert you to new additions to the "inventory"
• Block the reading of any RFID you carry
• Spoof a given RFID

More details at http://www.rfidguardian.org/ (in English)