This is a response to dogsrcool2me's 'RFID Secure Wallet.' It's the same concept, except it's made out of two soda cans and some packaging tape. And it's very sloppy. In fact, I'm quite ashamed of my sloppiness.

I would suggest using duct tape, but I didn't have any around. So, here we go.

You'll need:
hobby knives/scissors
2 soda cans
packing tape/duct tape
felt tip pen
sand paper

Step 1: Step One

Get a hold of two cans of soda. Either dump them out or give one to your very close, anonymous anarchist friend.

Step 2: Step Two

Cut the cans so that you have two nice strips of aluminum. sand down both sides of the aluminum and flatten them down if you can(I tried. All I did was put them under a big book. It didn't work.)

Cut those two pieces of aluminum in half.

Remember to recycle!

Step 3: Step Three

Wrap your tape around the pieces of aluminum individually, then bind the four pieces of aluminum together into pairs. After that, tape those pieces together so that you have something that resembles a wallet.

Step 4: Step Four

Now, put your RFID card in there and put it up to a RFID scanner and see if it works.
I would appreciate it if someone who has an RFID card an scanner tries this.
Again, sorry about how sloppy this is. I hope it gave everyone a good idea of what I'm thinking.