WHEN people think of hacking, they invariably think of the pale 14-year-old kid who breaks into computer systems to wreak havoc. But before hacking went over to the dark side, it was actually a noble art of fiddling and modifying hardware or software to create unexpected results. Just like you can hack your Xbox to turn it into a powerful media centre, you can hack the business world and make money for yourself while saving others money, and all in a legal way.

People use hacks all the time but probably don't know about them. The simple text message is a hack. The technology for text messaging originally intended it to be used for sending software updates and configuration settings to phones. Instead other people decided to use it for another purpose and send each other text updates. Text messaging is now a multibillion-euro business and has created a huge new market that was once never imagined.

It is this reimagining, and repurposing of hardware and ideas themselves that is the philosophy of hacking. In tech circles, a hacker is someone you have on your team who tweaks your system or manages to do something with the system that others have said was impossible. In boxed-in environments where there are few resources, a hacker becomes very useful.

In TV land, MacGyver and the ATeam were hackers. MacGyver would take some pipecleaners and a few plastic bags and next up he'd be hang-gliding off a mountain, while the A-Team would take a washing machine, some sheets of metal and a blowtorch and build a tank. Luckily for the A-Team there were always sheets of metal and blowtorches in the sheds they found themselves locked into.

In Cuba, hardware hackers keep cars from the 1950s still chugging along while other Cubans, in a bid to escape to the Free World, have converted buses and cars into boats to get them to Florida. It is this ingenuity that gives end users more freedom and it is this hacking of the system that annoys large corporate entities that would rather the status quo remains unchanged.

In the music download world, the website Allofmp3. com is the biggest thorn in the side of record companies since the old days of the carefree Napster service. (Napster has since been neutered and turned into a restrictive legal music download service. ) Using the very loose copyright laws in force in Russia, Allofmp3. com sells music online at a tenth of the price that other services such as iTunes sell at.

Record companies see little or no royalties from the sales and Allofmp3. com has grown to be the second-most popular music download service after iTunes.

Fon is a new project that intends to change the wireless internet business by building a virtual worldwide network.

The only infrastructure Fon has are the wireless modems it sells. These special modems share some of your broadband connection with other people. In return for sharing, you can connect to any other Fon modem around the world for free. For those who travel a lot, Fon is quite useful and can drastically cut down on internet access charges while abroad.

Antoin O Lachtnain is an evangelist for Fon in Ireland. I asked him if Fon was a business and technology hack.

"Definitely, " he said. "It's using the technology in a way which is unexpected. It isn't specified in the original wi-fi spec, but that doesn't mean it isn't a good use of the technology. Of course, it isn't just a technology change, it could have an impact on the whole ISP business as well."

Irish software developer Donncha O Caoimh works for Wordpress, a company that creates software to allow people to build blogging websites. Donncha reworked the code of existing opensource software and turned it into an application where multiple users could all write on the same blog. This soon turned into the Wordpress application and a million-euro business has grown around it. Wordpress now powers about seven million different blogs worldwide.

Pat Phelan is the epitome of a business hacker. He has released a string of new products this year that sees him go head to head with the giants of the telco world. One of his products, Allfreecalls. net, allowed Americans to make international calls for free after phoning a special number in Iowa. Iowa was the setting for the film Field of Dreams, in which Kevin Costner build a baseball arena in a corn field after being told by whispers that if he built it, they would come.

Phelan built a service and the calls did come. The rural telco he used for his service reportedly saw call revenues increase from 2,000 a month to 2m a month in a short space of time, with Americans rushing to reach out to people around the world for free. Phelan said he was able to offer such a service using a hack in American telecoms regulations.

"There are a number of states in the USA where the FCC [telecoms regulator] were worried about the in-state telecoms infrastructure and the lack of funds being spent on upgrading the network. The FCC launched a special fund called the 'Universal Fund', which means that phone conversations that terminated in-state should carry a levy. This levy is between one and four cents, depending on how the call comes in.

We have placed equipment in Iowa, and using the fee received for in-state termination, we allow outgoing international calls to be free."

American phone giant AT&T was not impressed with the way Phelan exploited the funding loophole and has since pressurised Phelan's Iowa provider to terminate the deal. Phelan isn't discouraged though, and plans to bounce back and continue providing cheap international calls through new means.

He has also moved into the Irish market to do something quite similar with Allfreecalls. ie.

Not content with taking on the phoneline operators, Phelan has also launched a service to route around high mobile roaming charges. Called Roam4free, this service supplies you with a new sim card to use in your phone while travelling. With this service you are not charged anything to receive calls in most countries and outgoing calls are routed though a VoIP gateway, reducing the cost of a call by up to 80%, depending on the country. The service works by using an Estonian mobile phone company that doesn't charge fees for receiving calls, while using a much cheaper VoIP service to reroute your outbound calls.

Call them mavericks, call them chancers, but business hackers are our very own A-Teams and we all benefit when their plans come together.