Anthony Doesburg: Enforcing new phone laws will be a hard cell

As cellphones become satellite navigation devices and sat-navs become phones, there's potential for plenty of confusion when the police begin enforcing the ban on handheld cellphone use while driving.

In Australia, where the law already says thou shalt not drive and use a mobile phone - unless it is in a holder fixed to the vehicle, or you can operate it without touching it - internet forums hint at the murkiness that lies ahead.

Users of Apple's iPhone complain that they've been fined for using the devices as navigation aids.

A person posting to the digihub forum of The Age website wrote that he'd been pulled over while his phone was on the dash in navigation mode and, despite telling the officer he could prove he had not been calling or texting, he was landed with a A$250 ($305) fine.

The same argument could arise if you were behind the wheel and using a phone to play music or to do any of the countless other things they're increasingly capable of. And, for that matter, in-car navigation devices already do more than help you find your way.

They can play music, display photos and, in the case of US manufacturer Garmin, will soon have a built-in phone. Even in straightforward route-finding mode, they can be distracting enough.

How the police navigate through this new area of potential contention is sure to be diverting, particularly for lawyers.

Cheap global positioning system (GPS) receivers are at the centre of this new technology convergence trend. The range of GPS-equipped gadgets is growing fast and gets weirder by the day.

If you thought golf was already enough of a loafer's sport, some courses are making it more so by putting GPSs in golf carts. If the pin is out of sight, the GPS helps them select the right club by displaying where they are in relation to the green.

But GPSs are also finding their way into the hands of more active sportspeople. New Zealand Tour de France rider Julian Dean, part of the Garmin-Slipstream team, uses a Garmin device to track everything from heart rate, cadence (speed of pedalling), speed and altitude.

Garmin wristwatch GPSs for runners, linked to a wireless heart rate monitor, record every agonising detail of their run, which can be uploaded to a computer. Run the same course several times and you can see whether you're getting faster and fitter, or the opposite.

At the wacky end of the spectrum, a Brazilian lingerie maker is selling a line with a pouch for a GPS; not, apparently, so a jealous husband can keep tabs on the wearer, but for her personal security.

Serious GPS uses outnumber frivolous ones, but they can sometimes go awry. Atlanta broadcaster WSB-TV reported in June that a family had their home skittled by a demolition crew that had been given GPS co-ordinates for the house they were to take apart.

Their GPS led them to the address, they did their work - but they'd been given the wrong co-ordinates.

A warning of GPS-wrought disaster on a much wider scale was issued in a May report by the US Government Accountability Office (GAO). Its interest stems from the fact that the constellation of GPS satellites is managed by the US Air Force.

GPS data is provided free of charge, as a by-product of the security use the US puts it to. The GAO acknowledges that the GPS network has become a "key tool in an expanding array of public service and commercial applications at home and abroad".

Hence its concern that the USAF might not be able to get new satellites into the sky quickly enough to avoid interruptions to the service when existing ones begin reaching the end of their life next year.

Matt DeMoss, of Garmin Australasia, says the company isn't alarmed at the GAO report.

DeMoss says when 20-year-old Garmin - which last year sold nearly 17 million personal navigation devices, more than any other manufacturer - asks itself where PNDs are heading, the answer is handsets.

That seems a safe bet. Last week TomTom, its European rival, released software that brings turn-by-turn navigation to the iPhone, a step up from the phone's rudimentary pre-installed Maps application.

Garmin is converging from the other direction, bringing cellphone capability to its in-car PND range with the Nuvifone, expected to be available here within 18 months.

With the law tightening up on mobile phone use in cars, how long before these devices come with a radar detector to warn when the highway patrol is in the vicinity?

Found in space

The international GPS system relies on signals from 31 orbiting satellites, managed by the US Air Force. The oldest satellite still operating was launched in November 1990; the newest this month.