http://nz.parkmobile.com/
You put the app on your phone, you punch in the code for wherever you're parking, it tells the system you're parking there, and then when you leave it charges you for the time you were there when you "log out".
I don't see the WCC adopting it any time soon as it might be a bit to difficult for their hordes (Pack/Flock/Scrum/Murder ?) of meter reader vultures to cope with, but it does mean less mucking around at the parking buildings that use it - no more dealing with "out of order" ticket machines or loose change etc.
The only obvious downside is that it does mean another agency holding your credit card details, hopefully in an encrypted fashion of course.