bags and wallets/billfolds block radio waves

I was surfing around and stumbled across the Oakley Vertical Computer Bag 3.0:
"...If you have a Bluetooth-enabled PDA or mobile phone, the accessory pocket uses RF shielding to help prevent unwanted access by nosey jerks."

With so many cards (identification/access/etcetera) having RFID in them, also take a look at:
a RFID Blocking Passport Billfold...
a RFID Blocking Wallet...

and Mobile Edge has a couple of wallets.