here you go. See link.

Here is a link that might be useful: RFID

I was in a WalMart and one of the associates was waving one of those "gun" handheld computer things they use in front of a wall of jeans. As she went along the "gun" was beeping. I asked her what she was doing and she told me she was taking inventory. When the gun stops beeping, it had captured every item (at least all the functioning RFID tags). Sure must beat scanning every single item.