Sydney  - Jon Steel, planning chief in Sir Martin Sorrell's London-based advertising company WPP, is now living in the Australian city of Perth, half a world away from his boss and from his former office.

"A lot of work I was doing within the group was done by video conference and email anyway," Steel explained. "I can play a similar role to what I've been doing globally."

That's the modern workplace: any country, any time zone, anywhere there's a wireless network. Technology has overturned the notion of company time and personal time.

"Work used to be Monday to Friday, it used to be nine to five, it used to be 11 months of the year with one month off. All of those edges, those hard edges, are breaking down," said Bernard Salt, a demographer with international business consultancy KPMG.

"These days, who doesn't check their email or Blackberry over the weekend? You might not respond to them but you remain connected to work. I call it a permanent state of workplace arousal," he said.

Salt says what matters nowadays is not keeping office hours but keeping up with key performance indicators (KPIs), by deliverables, by output.

"It's output-driven work as opposed to protocol-driven work," he said. "Work has broken out of its cage and is marauding around taking lots of other bits of the week."

Examples of this abound: people firing up laptops in cafes, checking emails and voicemails as they walk through the arrival hall at airports, working on presentations on the train.

It's not just that employers are stealing time from their staff. It's a two-way street. Those who were up late at night writing a report might spend half an hour of company time doing their internet banking and even longer on social networking sites.

"Now, through technology, you can blur and blend, completing bits of work at home and completing bits of home life at work," Salt said.

In some workplaces, where bosses perhaps feel guilty about the work-life balance tipped too much in their favour, valued employees get their dry cleaning done and other errands run for them.

Salt sees a downside for those in a permanent state of workplace arousal. Never disconnected from their jobs, they are unable to be completely free in their home life. Relationships suffer. Eventually, work can suffer too.

Unable to find a work-life equilibrium, harried executives simply drop out. They hand back the company laptop, Blackberry and mobile phone.

Senior staff who insist on breaking free are not always praised for their courage.

As secretary of Australia's Treasury Department, Ken Henry is the government's key finance adviser. A year ago, he took five weeks off to look after a colony of endangered hairy-nosed wombats in a place where he couldn't be reached by mobile phone.

The prime minister was asked questions in Parliament about his absence at the start of the global financial crisis. It was considered extraordinary that he should be incognito for such a long time.

Adelaide University researcher Barbara Pocock defended Henry, saying "annual leave is a primary protection against burnout at work - it's there for a reason."

What Salt says is that employees need to monitor their own working hours and make sure technology has not allowed work to overpower all else.

"There are positives and negatives," he said. "But with work breaking out of the cage, you have to guard against its tentacles reaching out and claiming more and more of your life." (dpa)