They may have a point. Wi-Fi clouds consist of thousands of Wi-Fi antennas, or "nodes." Each node is basically the same kind of Wi-Fi router that, say, a coffee shop might use. With a Wi-Fi cloud, a couple dozen of those routers are placed at regular intervals over a square mile, and they all communicate with each other and with a single, wired Internet connection. The mesh works much like the Internet itself. Data flows from node to node, depending on which one will give you the strongest signal. A failure in any single node won't bring the network down, because the other nodes will fill its place. Every mile or so, another wired connection is plugged in, and another set of nodes is put up - most of which are attached to lightpoles that also provide power. The result is a chain mail of connectivity that's accessible anywhere outdoors, and can be brought inside with the purchase of a separate wireless antenna.

"It's a completely towerless system," says Joe Hamilla, director of engineering for Motorola's Mesh Networks Product Group. "So instead of having to buy real estate, go through planning boards, and get approvals,­ these things hang on existing lightpoles and buildings. No one says they don't want this in their backyard, because they don't even see it."

Installation is quick, too. In Philadelphia, officials think they can install a square mile's worth of nodes in half a day's time. That's about how fast things went in Chaska, Minnesota, one of 29 smaller U.S. communities already covered by Wi-Fi clouds. That entire city got Wi-Fi access in just a few weeks and at a cost of less than $600,000. Service there costs residents $15.99 a month, and nearly a quarter of the population is signed up.

Then again, Chaska is not exactly a bustling metropolis. Just 18,000 people live in the city's 16 square miles. By comparison, Portland, Oregon, which may be the first to follow Philadelphia, has 538,000 residents living in 130 square miles. Philadelphia, meanwhile, has 1.5 million people in 135 square miles.

In cities that dense, there's a lot of stuff flying through the air. Cell phone calls, cordless­-phone chatter, two-way radio transmission, Donovan McNabb passes. That kind of thing. And with all that competition, no one knows if a big-city Wi-Fi cloud will work until it's built. "This kind of network has never been deployed in a city as dense as ours," says Neff, Philadelphia's CIO. "But we're confident in the technology."­

Right. Technology. Regardless of how the politics shake out in the cities pushing Wi-Fi clouds, the march of technology is likely to be unstoppable. Perhaps someday all cities will have Wi-Fi clouds. Or maybe we'll all log into WiMax networks, a successor to Wi-Fi where a single wireless connection can be sent over several miles. And with cities desperately looking to gain a competitive edge on each other, more wireless Internet access is almost certainly on its way soon to a city near you.

“After a while, Wi-Fi is going to be like cell phones are today,” says Bert Sperling, president of Sperling’s Best Places, a research firm that helps Intel compile its annual list of Most Unwired Cities. “It used to be with cell phones that you worried about where you were going to get coverage. Now coverage is everywhere. And so will this wireless Internet connectivity be everywhere.”