Here in downtown Seattle I live in a building that's pretty much like Fort Knox. They gave me an RFID fob to get me pretty much everywhere. In and out of the garage, elevator, front door, etc.
Had some problems in the past leaving the house without my keyring and getting my ass locked out, a real PITA, so I started carrying an extra RFID badge in my wallet. Trouble is, at about 4mm it's too damn thick for an already overstuffed wallet.
So at happy hour at Kell's today in a vodka-induced epiphany, I peeled open the card with my knife, removed the RFID guts, and laminated the whole thing at Kinko's. It works like a charm!
Here are the results:
And from the side you can see it's only about 1mm thick and has some flex:
Cool beans, except everyone who's seen it wants me to make one for them.