This is my Firefox bankcard:
My bank offered the possibility to use my own image on my bankcard. You could order it through a web interface, so I uploaded the Firefox logo onto mine and picked up the card a few days later from the bank.
The graphic for the Firefox logo can be found in the Mozilla Style Guide.
My bankcard became the number one story of the day on Digg, possibly becoming the most seen bankcard ever... Below is a screenshot of Digg when the story was number 1.
Over the years, each new bankcard I got had the Firefox logo on it. The recent ones actually look nicer in my opinion (like the one below from 2011). The only thing is that by now it's the old Firefox logo, but still.