This sounds really interesting:

This fall, San Francisco will test 6,000 of its 24,000 metered parking spaces in the nation’s most ambitious trial of a wireless sensor network that will announce which of the spaces are free at any moment.

Drivers will be alerted to empty parking places either by displays on street signs, or by looking at maps on screens of their smartphones. They may even be able to pay for parking by cellphone, and add to the parking meter from their phones without returning to the car.

I do question the premise though that this will ease the fighting over spots:

Solving the parking mess takes on special significance in San Francisco because two years ago a 19-year-old, Boris Albinder, was stabbed to death during a fight over a parking space.

“If the San Francisco experiment works, no one will have to murder anyone over a parking space,” said Donald Shoup, a professor of urban planning at the University of California, Los Angeles, whose work on the pricing of parking spaces and whether more spaces are good for cities has led to a revolution in ideas about relieving congestion.

Depends on how they implement it, I actually think you may have the reverse situation where everyone drives like mad trying to descend on that last parking spot causing more fights and chaos.

[ nytimes.com ]