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."

Not everyone is quite so wistful. Telecom and cable companies opposed the Wi-Fi cloud in Philadelphia, and they're fighting similar plans in big cities from coast to coast. Dave Mock, an author and analyst who specializes in wireless communications, says telecom and cable firms understandably don't want the government competition. "But," he says, "in most cases, municipalities are taking open bids to build citywide networks." Conceivably, then, telecom and cable firms could build and operate them. Nonetheless, legislation favored by the telecoms is moving through 15 different statehouses nationwide. Most of the laws would block cities and counties from building their own Wi-Fi networks or force them to first seek voter approval. Legislators say they're concerned that the networks will end up costing taxpayers too much.

That's exactly what Aaron Dobrinsky,­ CEO of RoomLinX, a top provider of wireless Internet services to U.S. hotels, including the ritzy Chateau Marmont in Los ­Angeles and the Mercer in New York's SoHo, expects. He says municipally owned Wi-Fi clouds are "a terrible idea. They are … a very short-sighted initiative by cities that are grossly underestimating what it takes to support such a network. So called 'free' wireless will end up costing consumers­ more money than they currently pay to access the Internet." 

Wi-Fi plans in most big cities don't call for taxpayers to pony up, though. In Minneapolis, city leaders want a private firm to run the entire operation, paying the city a portion of their revenues. In Portland, a private firm would also be contracted to build and run the Wi-Fi network. The city would, in exchange, offer the firm rental space on the tops of buildings - a prime spot for urban cell phone towers. Overseas, Taipei is also calling for private companies to pay for construction and operation of its Wi-Fi cloud.

That's an expensive proposition, but not nearly as pricey as offering cable-based high-speed Internet access. It costs between $20,000 and $50,000 per square mile to build a Wi-Fi cloud. That's four times less expensive than the cost of burying high-speed data cables under city streets. Cities aren't worried about excessive upkeep costs, because they say the networks are low-tech, low-maintenance operations.