Small installations of RF shielding don't have to be expensive, and the basic concept of a Faraday cage can be extended to all kinds of small everyday objects. Leather wallets sandwiched with a conductive RF-shielding layer can prevent RFID scanners from reading personal information implanted in everything from RFID-enabled access control cards to some credit cards; they're widely available for as little as US$15. For those favoring a more DIY route, several Web sites have information on how to make an RFID-blocking wallet with duct tape and aluminum foil.

Who'd want such a thing? Quite possibly, you. U.S. passports are now set to include RFID chips, and future editions of U.S. currency might be RFID-enabled too. Expect further expansion of the burgeoning market for RFID-blocking wallets, passport holders and other paraphernalia for the paranoid and/or privacy-savvy consumer, from companies such as Emvelope and DIFRWear, which sports the motto "Faraday caged apparel." A sure sign of growing consumer interest? According to the Digital World Tokyo blog, a Japanese company is offering Faraday-cage card holders featuring the visage of that fierce data protector... Hello Kitty.

Dayal is a freelance writer in New York.

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