It is a technology that uses very small and thin circuits (could be as thin as a sticker) to identify items (humans, products, etc.) with NO need of line-of-sight interaction (just like what we do while reading the bar code).

For example it could be used for shopping in the following scenario: you will only need to pass the cart next to an RFID and do your own self-checkout without the need to pass the items one by one!

The more interesting news is that RFID circuits could work with NO need for power supply (no need for a battery or power source) that what enables it to be embedded in human buddies and help manage medical records and other ID-based services more effectively!

Aparently Wal-Mart is already using this technology! Would we one day have these tracking devises implanted at the day of birth in each person? Maybe it is a huge in-thing now to be implanted in Mexican migrant workers in the US, which I am sure would make the US government and the anti-humanity persons happy! I understand that such a technology might be helpful if a car is stolen, tracking a spaceship, but really, some things need not be tracked- like people.