RFID is the concept of putting a little wireless chip into pretty much everything allowing you to track and identify items with a computer and an antenna. Chances are your credit card has one in it, and there’s one in your passport if you’ve gotten it in the last few months. There’s the potential for some interesting things with RFID, (you may remember the commercial of the person walking through the grocery checkout without stopping) but the control is lost to the user since anyone with a reader nearby can check all your RFID tags at will.
So three researchers from the Netherlands submitted a paper about an RFID firewall. It queries all your currently held RFID chips and proxies answers to any other readers, including giving no answer at all. It gives the fine grained control back to the user and is a very, very interesting development in personal privacy in an world where everything has a chip and is wireless.