Here's a cart pulling a donkey story from Houston: A fascinating idea here that Houston will probably build a Wi-Fi network to handle credit-card payments from new parking meters. Building that network will save them money over other alternatives. They might then open that network to the public. Where there are parking meters, there are people.
Vancouver International Airport - Vancouver, Canada, supposedly has parking meters tied to SMS so that the system can send you an SMS "from the meter" and you can reply to the SMS to extend your time; the payment amount is added to your cell phone bill.
In Eastern Europe, in some places (Budapest, perhaps), Esther Dyson reports that one can pay and renew parking meters via SMS as well.
Way cool! Would love to have that here!