The lure is understandable. Wi-Fi use is spreading. Today, most laptops have Wi-Fi cards included. Many desktop systems come with Wi-Fi, too. The Telecommunications Industry Association says spending on wireless communications will jump from $158.6 billion this year to $212.5 billion by 2008. Even so, there are still only 50,000 Wi-Fi hot spots worldwide, according to one estimate. Maybe the last hotel you stayed in was one of them. Or the coffee shop down the street might be Wi-Fi enabled. But the closest hot spot isn't always that convenient. So any city that's totally wireless would stand out among its peers.

"Municipalities have to do more and more innovative things to attract businesses and residents," says Rick Rotondo, director of marketing for Motorola's Mesh Networks Product Group, which is working with several cities to install Wi-Fi networks. "Having Wi-Fi is very appealing, particularly to younger citizens."

TO THE YOUNG, of course, goes the future. And the future is what these citywide Wi-Fi networks are all about. In Philadelphia, officials promise their Wi-Fi cloud will send the city speeding toward tomorrow. Laptop­-toting students and business travelers will fill public squares to do research and send e-mails. City workers will take service requests online, without leaving their vehicles. Tourists using laptops or PDAs will follow online walking tours of the city's ­numerous historic sites.

It's not exactly hovercars and robot maids, but for a city usually thought of for its past, that future vision is a leap forward. "People are already seeing Philadelphia in a different light because of this project," says Dianah Neff, Philadelphia's chief information officer. "It's not just the historical Philadelphia people think about now. They also think of us as a 21st-century digital city."