There is a quiet power shift occurring in the broadband industry that promises to dramatically change how we access the Internet and its many features. Instead of DSL, digital cable, cellular, and POTS (Plain Old Telephone System), we will use high-speed wireless connections (Wi-Fi) for nearly everything.

Wi-Fi itself isn't especially new. Countless people have Wi-Fi in their homes and use it to log onto the Internet from any room having a computer equipped with a wireless modem. Thousands of businesses, college campuses, and other facilities also have Wi-Fi networks. In many places, the services are available at no charge to anyone who enters the area.

However, what's new is that so many Wi-Fi networks have been set up, the zones often overlap forming wide-scale "hotspots." In many cities, a person can be nearly anywhere in the central business district and have Wi-Fi services. Although many systems are restricted, the trend is to make them public.

Many municipal governments have noticed the popular Wi-Fi trend and its low cost, and are deciding to offer the services themselves. San Francisco recently contracted with Google (GOOG, Nasdaq) to create a comprehensive Wi-Fi network able to serve 750,000 city residents. Earthlink (ELNK, Nasdaq) is doing the same for Philadelphia. Dozens of other cities are also creating Wi-Fi networks to promote business and meet the public's need for broadband services. Before long, Wi-Fi will be available nearly everywhere.

Even some rural areas are installing Wi-Fi networks. In Oregon, for example, Umatilla and Morrow counties have a shared Wi-Fi system that covers 600 square miles. Cowboys, Indians, the Marshall and hundreds of other people use EZ Wireless every day.

The next big wireless development that's just becoming available is Wi-Fi telephone. First-generation systems were awkward to use because both a laptop and a special phone were needed to make and receive calls. However, new phones are being introduced that access Wi-Fi systems directly. Lowe's, the building products giant, has converted several stores entirely to combined Wi-Fi voice and data systems. The company's SpectraLink (SLNK, Nasdaq) phones are dual-mode--they use both wireless and the regular POTS system.

Eventually, people may carry multi-use phones that combine cellular and Wi-Fi capabilities. Motorola (MOT, NYSE) hopes to have such a phone available next summer.

Incredibly, Vocera Communications, a privately held company, just introduced a Wi-Fi telephone that clips to a person's lapel, In fact, the company's Communications Badge is easier to use because it is voice-activated. Speak a name and the phone badge makes the call.

As you might expect, the cellular industry is less than happy to see the spread of Wi-Fi technology that threatens to make their systems obsolete--at least in urban areas. Not only does Wi-Fi do more, and usually faster, it's generally free or available for very little money. That's a tough combination to beat.

Nevertheless, some cellular companies are introducing Wi-Fi networks of their own in the theory it is better to compete with themselves than to give ground to outsiders. T-Mobile, for example, has 6,000 hotspots located in Starbucks, Borders, and other locations.

DSL providers are on the same slippery slope as cellular services, and for the same reasons. Digital cable still has a speed edge over Wi-Fi, but many customers may decide the difference is not worth $40 or $50 a month. POTS, of course, has been heading for dinosaur heaven for several years.

Wi-Fi's competitors won't go down without a fight, though. They are well established nearly everywhere with millions of satisfied customers. In addition, Wi-Fi's opponents have a lot of clout with local governments that are paid handsome licensing and access fees. However, Wi-Fi is so popular, and it is expanding so quickly, it probably can't be stopped.

As with any rapidly evolving technology, wide-area Wi-Fi is still working out some kinks. Users sometimes lose their connections when moving from one wireless zone to another. Standards are also lacking for some systems. And pricing plans are still being worked out. But, Wi-Fi is here, it's fast, it's cheap, and it does most jobs very well. It's the most promising computer and telecom development we've seen in years.