[rstrahan]

We wrap a piece of aluminum foil over the chip-enabled cards. They also make wallets that shield the cards from unintended electronic intrusion.

[Yogafist]

This might be a little easier.

http://www.staples.com/rfid+credit+card+sleeves/directory_rfid+credit+card+sleeves

[Mich Patriot]

I don't use a wallet anymore...I use a "Slim Clip" (ebay - under $10 incl. shipping)...cash on one side, cards on the other. I hate carrying an overstuffed wallet, so I keep just the bare essentials in the clip, and a wallet with my lesser used cards in my locked vehicle. I carry the clip in the front pocket, which I also prefer. I assume since metal covers the whole card except about 1/4 inch on the end, it would protect the cards from being read?