Are you too drunk to drive home, but sober enough to use the QR code reader app on your phone?
This ad hanging over a urinal in a bar bathroom has a QR code that automatically calls a cab.
You could argue that if I pull out my phone to use a QR code, I could just look up and call a cab company myself. But does the novelty factor make up for it?
At least it's a more practical placement than this taxi top ad for a similar Jose Cuervo app.