Some car parks in the UK have ticket machines which ask for the car's registration plate so that the ticket is bought for a specific vehicle (this stops people giving half used tickets to other vehicles coming into the car park)
This is the letter and number interface on the machine. It has to be tall and narrow as the ticket machine is tall and narrow. I (and clearly the people who I had to wait behind) had trouble quickly picking the letters and numbers from the keypad.
How could it be improved ? ( A numberplate has a AB12 CDE format)