Australian hackers have taken the practice of looking for open wireless networks to new heights.

Before now many curious hackers have taken to cars and bicycles to look for wireless network nodes that are free for everyone to use or are inadequately protected.

But the Australians have them all beaten by using a light aircraft to fly over the city of Perth and look for the wireless nodes from 460 metres (1500 feet) up.

During their flight the group found up to 95 wireless nodes.

Sky-high net

To find the nodes the team, who are involved with the e3 wireless weblog, used a handheld iPaq computer and a laptop fitted with software that can spot wireless networks.

The four flew in a Grumman Tiger aircraft and followed a looping flight path over the Australian city.

Wireless networks are popular in Perth. It has more than 400 nodes operating within it.

Many companies and organisations are turning to wireless networks to link computers together to replace some of the cables usually needed to connect machines.

Some of the networks are being set up to let anyone get fast and cheap net access and advertise their existence. Others can be found or used because they are doing a poor job of securing them.

The group dubbed the practice of using a plane to find wireless nodes "warstorming", a word made up of "wardriving" and "barnstorming".

In the early days of computer hacking many people programmed their machines to dial through long lists of telephone numbers searching for ones that answered with a data tone.

That practice became known as "wardialling". It has inspired several other types of searching including "wardriving", which involves using a car to look for wireless nodes, and "warwalking" which is done on foot.