Earlier this month, Philadelphia - one of America's oldest and most historic cities - thrust itself onto the technological frontline by announcing plans to build the biggest municipal wireless internet system in the country.

The 135-square-mile network will be built and managed by Earthlink, and will offer low-income residents a service for about $10 (£5.70) a month.

A clutch of other cities are hoping to follow suit with free or low-cost services aimed at reconnecting poor communities, growing local businesses and giving new flexibility to the emergency services.

In a couple of weeks, San Francisco will announce the results of its call for proposals on providing a wireless service to the city's 750,000 inhabitants.

One bid that sent shockwaves through the industry came from Google, which offered to blanket the city with free wireless high-speed internet access - funded by advertising.

San Francisco Mayor Gavin Newsom said: "This is inevitable - wi-fi. It is long overdue. It is to me a fundamental right to have access universally to information."

'Wasting their money'

Where traditional wired broadband networks required massive investment, new technology means wireless networks can provide similar levels of service, at a fraction of the cost.

But the big telecoms firms - who have invested billions in cable or fibre optic links to millions of US homes - are waging a legislative and PR campaign against municipal initiatives.

Currently there is a bill going through Congress, sponsored by the Texan Republican Pete Sessions, that aims to ban cities from building municipal broadband networks under most circumstances.

But there is also an opposing bill in favour of the city networks, a bill backed by Republican John McCain and Democrat Frank Lautenberg

There are already fears that the rise of Voice Over Internet Protocol (Voip) calling - where net-connected computers can make cheap phone calls - will damage profits.

The companies argue that public competition puts private enterprise at a disadvantage and that cities are rushing into the market without a sound business case.

One industry group has just launched a new TV ad backing a bill before Congress that opponents say would empower the private sector to block community internet services.

Elsewhere, telecoms and cable giants are lobbying hard and spending big at local and national levels.

Verizon, which will compete with Earthlink when the Philadelphia project goes online sometime in 2006, told the BBC it did not support a ban on municipal networks, but said the city's move made no sense.

Link Hoewing, Verizon vice-president for internet policy, said officials were at risk of "wasting their money", adding: "I think the market has done a good job of addressing the issue already."

Supporters of municipal broadband disagree, however, saying the big business model is failing.

Rural access

Recent figures suggest that since 2000, the US has dropped from third to 16th among nations worldwide in terms of per capita broadband access.

Studies suggest that 86% of households with income of more than $75,000 have broadband access. But the share is just 38% for those with an income of less than $30,000.

Huge areas of US countryside outside major towns and cities are also poorly served.

Ironically, one of the frontiers of wireless accessibility is found in a rural swathe of Oregon, which is thought to have one of the world's largest wireless hotspots.

Here a 600-square mile cloud of wireless connectivity provides free, high-speed internet coverage to schools, emergency services and residents alike.

The brains behind the network is Fred Ziari, an Iranian immigrant who is CEO of EZ Wireless, a Portland-based hi-tech firm that contracted with local authorities to provide the wireless service.

Police in the city of Hermiston now carry wireless computers with which they can download images from video monitors, floorplans of buildings and, soon, access a database of suspects' fingerprints.

Mobile future

The Free Press, a non-profit group that favours the development of municipal wireless, says that across the US there are hundreds of community internet initiatives, some wireless, many not.

In the Texas state capital Austin, a local not-for-profit group runs a network of more than 100 hotspots, with 57,000 registered subscribers, providing free public Wi-Fi.

Seventy percent of Austin Wireless' (AW) partners are small businesses like cafes and book stores who want to attract customers with free internet access - the rest are city-controlled venues like parks or libraries.

The group's president, Richard MacKinnon, hopes the initiative will be a model for other cities across the US and beyond. Already there are four AW hotspots in Bangkok. Another is run by Fairplay, an international shipping periodical based in Redhill, England.

Mr MacKinnon told the BBC: "If we roll back time to when people said you'd one day be able to use a mobile phone almost anywhere in the country, you might not have been convinced.

"For the most part it has come to pass, but in many ways it is not the ideal scenario we would have envisioned at the outset with coverage or with costs.

"If you ask where we will be with wireless in the future, I'd say look at the phone market and ask yourself if you are happy."