I recieved this today. It appears that American Express has already built their own USB duckys. In this
you can see that this usb card is a HID keyboard that brings up the windows Run command and keys in their webpage. I took this thing apart to see the what was on the board.
Up close to the chip
I haven't been able to find out about the chip that is on the board but it would be great to see if they can be acquired!