Have you ever seen a business card with a computer chip embedded on it? This one does. It has an ATtiny85 microcontroller chip that stores all your personal details. You plug it into an USB port of your computer, and find the details about the person opened into a text editor. The firmware uses V-USB (which is a software only implementation of USB) that allows the ATtiny85 microcontroller to act as an USB keyboard device, and type the stored info into the open text editor window.
For more detail: USB business card with a computer chip board using ATtiny85 microcontroller