Park and Pay with mobile phone and RFID

Parkmobile, a company specialized in phone-parking, designed a service allowing drivers to start and end the parking payment with a phone call.

Drivers fix a RFID transponder card to their windscreen so that parking attendants can check electronically whether a payment has been started.

No need to predict how long you are going to stay and there is definitely less risk to pay fines.

See The Register