After mostly-not-seriously Googling for a way to build a Faraday cage wallet to protect my overly promiscuous passport, I found:

• This guide to making RFID-proof pants pockets, which linked to
• This source of EM-shielding fabric, who also sell
• This range of EM-proof shirts, underclothes, hats, aprons and mosquito-net-like bed canopies for those people who are really worried about ambient electro-magnetic radiation.

"We slept well for the first time since 1998. The high pitched tone in our ears is much less under the canopy and we feel much less nervous. It's a wonderful feeling to be under the canopy"