Miami ? Here’s a new reason to keep your cell phone charged:

Parking in Coral Gables, Fla., home to 4,573 parking meters, has been made easier by the introduction this month of a park-and-pay-by-cell phone service – touted as the first of its kind in the country.

That’s right: Pay by phone. You pull up, dial a number, punch in a few keys and walk away without a worry. The meter won’t expire until you call again to log off.

“You can do that? Wow,” said an approving Kamran Saraf, a 25-year-old medical student at the University of Miami. He already had dropped a quarter in the lot behind the post office on Miracle Mile but subscribed to the service when he returned.

It took him 6 1/2 minutes to enter his credit card, e-mail, license plate and telephone number.

“It’s pretty cool,” Saraf said, having a V8 moment and regretting the fortune he might have made had he invented this service. “I actually thought of that a while ago, ‘Why don’t they let you pay by phone?'”

A subscriber’s phone will even ring when the maximum time for the meter is about to pass – and then the time can be extended without having to leave a meeting or interrupt shopping to feed more coins into the meter.

Mari Molina, the executive director of the Gables Business Improvement District, is thrilled to see something alleviate the one thing that keeps coming up as a deterrent for downtown shoppers: parking.

Kamran Saraf calls to sign up for pay-by-phone parking in Coral Gables, Fla. A private company is providing a way for drivers in Coral Gables to pay for metered parking over their phones.

“It’s innovative,” Molina said. “People come down and they start meandering and they forget about their parking meters, and we certainly don’t want them to get parking tickets.”

Which raises a question: Won’t the city lose revenue in having fewer violators?

“There could be some minor impact to the number of parking tickets we issue, but I think the service to the public far outweighs that,” said William Carlson, the city’s parking director.

The program has been offered in Europe and Canada, he added, but this is the first time it has been offered in a U.S. city.

More than 260 people have subscribed to the service either by phone or through the Web site since June 1, said Mich Ahern, a spokeswoman for Mint Inc., a Canadian company that provides electronic payment service solutions. A competing company has the same kind of service running at the University of California Santa Barbara, and it plans for pay-by-phone programs in cities.

“But Coral Gables is the first city to have this service in the U.S.,” she said. Mint will charge 25 cents for each parking “session” in addition to the time paid to the city – which is the same as it would be on a meter, except that the time is charged to a credit card. Debit cards are not accepted.

Customers have to register by calling (866) 729-6468 or logging in at www.mintinc.com. A Visa or MasterCard credit card number, license plate number, cellular phone and e-mail information is required for registration.

Once registered, customers can park at any meter on the street or in parking lots – except the 120 or so that have a 12-minute or 30-minute limit. Drivers then call a local number posted on the meter with the registered cell phone. The company will recognize that number when it calls in and welcome the customer to Coral Gables, then ask for the person to punch the space’s zone number, which is also clearly marked on the meter.

And that’s it. Customers must call again to log out and end the parking session, otherwise they will be charged for the maximum time on that meter, which is up to 10 hours. Mint also will send a text message to your cell phone after three hours in case you forgot to log out, Carlson said.

Customers also get a sticker in the mail that they can display on their rear bumper, to identify the car as a program subscriber’s to parking enforcement staff. But that’s not necessary, Ahern said. While the meter will read “expired,” the city’s parking enforcement officer will be able to check the driver’s status by punching the license plate into a hand-held computer.

The company will e-mail customers confirming transactions, and users also can review their transactions online anytime.

The new technology might be too much for some people, so the Gables will still have its meter key program, where motorists prepay for parking on a key that gives the equivalent time for a quarter for each time it is turned.

And, of course, meters still take good old-fashioned coins. That’s how Dayra Diaz prefers to pay for parking.

“I don’t like to give out my credit card number,” said Diaz, who does facials at a Coconut Grove salon and would rather ask strangers to change a dollar bill.

Saraf, the medical student, said he would likely use it – sometimes.

“If I’m parking long-term, two hours or so, it is definitely convenient. Especially if you don’t have change,” he said. “But if I’m going in some place for 10 or 15 minutes, I’d probably just drop a quarter in.”