By Mike Elgan | ComputerWorld

I’ve been predicting for years that Wi-Fi would get freer and freer until almost nobody could muster the gall to charge for it. Now, with the economy down and competition for scarce customers up, the trickle of free Wi-Fi hotspots is becoming a flood.

Fancy UK sandwich shop Pret A Manger announced that it will offer free Wi-Fi at about 170 of its stores across the UK starting today.

And while municipal Wi-Fi is dying an ugly, premature death in the United States, China is working on making the entire city of Beijing a giant free-Wi-Fi hotspot by 2011.

The airlines lately have been rolling out Wi-Fi that is the opposite of free: They charge way too much for it (there are few monopolies as perfect as the provision of wireless networking at 35,000 feet). However, Delta plans to start offering Wi-Fi on its puddle-jumper shuttle flights tomorrow. To promote the new service, they’ll offer the Wi-Fi free for the next two weeks.

Free Wi-Fi is breaking out at gas stations, on buses and even on French “bullet” trains.

Meanwhile, an open source Wi-Fi service called WeFi now claims 10 million hotspots worldwide.

As more free Wi-Fi hotspots emerge, customers increasingly expect Wi-Fi to be free.

Of course, there’s no such thing as a free hotspot. Somebody’s got to pay for it. Increasingly, however, companies are folding in the costs of supporting a Wi-Fi network into the operations budget, and spreading the costs across all customers. I think this is a good thing.

My belief is that the demand for free Wi-Fi is driven at least as much by the hassle factor as it is the cost factor. People just want to fire up their laptops or iPhone and be online. As Wi-Fi devices, including the iPhone, BlackBerry Bold and ubiquitous netbooks go mainstream, the provision of free Wi-Fi just makes sense for business of all stripes.