I spy with my little Global Positioning System

You are not, of course, so foolish as to wander into a communist state posing as a tourist yet carrying industrial quantities of surveillance equipment. But even if your immediate travel plans do not include taking on Cuba's formidable security service, hi-tech luggage could land you in trouble elsewhere in the world.

You are not, of course, so foolish as to wander into a communist state posing as a tourist yet carrying industrial quantities of surveillance equipment. But even if your immediate travel plans do not include taking on Cuba's formidable security service, hi-tech luggage could land you in trouble elsewhere in the world.

Ten years ago the foundation of the USSR was celebrated for the last time. Yet even though capitalism has supplanted communism, and Marx has been replaced by Mercedes as an object of reverence, life in the former Soviet Union can still be uncomfortable for travellers - in particular anyone hoping to bring in a Global Positioning System receiver.

GPS technology may strike you as both harmless and handy; the system interprets signals beamed from an array of geostationary satellites to reveal, to within a few metres, where you are. With the aid of a decent map, you can deduce the direction in which an approximation to civilisation might be found. A GPS receiver can, in short, prove useful for travellers trying anything tricky in the wilderness.

Yet the Kremlin remains highly sensitive to anyone using equipment that, in earlier times, could have been employed by MI6 or the CIA. Even though we are notionally on the same side these days, using a GPS device in Russia will be enough to get it seized and the owner arrested. If the authorities think you have compromised national security, you can be jailed for 20 years. And this is not one of those outdated laws that are never invoked; an American who was discovered using a GPS device near the southern city of Rostov-on-Don was imprisoned for spying (though he was let out 10 days later, following, it is believed, the payment of a heavy fine). After a lifetime of secrecy under communism, old counter-espionage habits die hard.

If a democratic nation can take such a hard line, it is hardly surprising that a one-party state like Cuba, battered for 40 years by a belligerent neighbour, takes a dim view of visitors turning up with hidden cameras and listening devices. As some Cuba-watchers stress, you don't fool with Fidel (often they use a stronger verb than "fool").

Genuine tourists to Cuba have little to fear. But bear in mind that all luggage is X-rayed upon arrival. Those apparently dozy-looking characters lazily watching the screens at the airport may be more alert and experienced than they appear.

* A piece of technology as simple as a camera may land you in trouble in parts of Africa. Much about the continent, from Tangier at the top to the Cape of Good Hope at the toe, is supremely photogenic: the people, the wildlife, the landscapes. But the US State Department has issued a series of stern warnings about the risks of taking pictures in certain African countries.

Security officials in Cameroon, for example, are "extremely sensitive about the photographing of government buildings and military installations". To make life tricky, many of these are unmarked. Break the rules, and they'll take your camera away.

Nothing too unusual about that, you might think; plenty of countries have the same sorts of rules. In neighbouring Nigeria, the prohibitions are similar but the range of punishments wider: "Penalties can include confiscation or breaking of the camera, a demand for payment of a fine or bribe, or roughing-up." Burkina Faso is even trickier, because you must first get a valid photo permit from the Ministry of Tourism, along with a list of things you cannot photograph.

In Tanzania, the definition of forbidden buildings extends to hospitals, schools and bridges, while Sudan broadens its prohibitions to include "slum areas or beggars".

The Democratic Republic of Congo (formerly Zaire), has one obvious photo opportunity: the river that gives the country its name. But "Photography of the banks of the Congo River is forbidden. Offenders may to be arrested, held for a minimum of several hours, fined and the camera may be confiscated."

* "We're looking for drugs."

When a couple of Americans say that to you, it is a good idea to listen. This pair were not in the market for buying some - they were staffing the US Customs post at Vancouver airport.

More well-travelled readers will protest that Vancouver is in Canada, an independent nation. Correct: but the Canadians have granted US Customs, and their colleagues in Immigration, the right to process America-bound travellers before they take off from the airport serving British Columbia's largest city.

For you, it usefully means the arrivals procedures can be completed in advance, meaning no formalities at the other end - you just walk away as though you have stepped off a domestic flight. And it is handy for the US authorities, too, because it saves them all the trouble of deporting you. They can decline your application for entry while you are still on foreign soil.

They can also make sure that illegal narcotics stay away from the United States. "We're like Kentucky Fried Chicken," explained one inspector, as his hound scampered around my backpack, luckily without showing much interest. "We do one thing, and we do it right."

THE SYSTEM has not yet been introduced at the obvious airports, Heathrow and Gatwick, which between them send around 20 million people to America every year. If the US authorities did ever set up bases in London, they would take interest in certain people who have recently confessed to experimenting with drugs.

Evidence of involvement in illegal narcotics is taken very seriously by US Customs. I wonder if the members of the Shadow Cabinet have any plans to visit America, and what the authorities' attitude would be to people who had publicly admitted smoking marijuana.

* You had to move quick to buy unrestricted £6 tickets for the Heathrow Express link from London Paddington to Britain's busiest airport. The Bargain of the Week that I recommended last Saturday on the UK's most expensive railway, proved too popular. Usit Campus, the agent offering the deal, now says the half-price tickets can be sold only as part of a flight. If the best deal for your chosen journey is with the company (0870 240 1010, www.usitcampus.co.uk), it's still a bargain.

* Back in Vancouver, they have been hard at work changing all the signs; well, half of them. Canadian Airlines' life-support machine was finally turned off this week. It has donated its vital organs (planes, staff, customers) to Air Canada. Luckily for travellers heading to Canada, plenty of competition remains, in the shape of British Airways, Air Transat and Canada 3000. The code CP - harking back to its former illustrious days as Canadian Pacific - has been airbrushed out of aviation history. The people at Canadian did one thing, and they did it right, but it didn't prove enough.

* A new competitor is on the way, in the form of Roots Air - a kind of Virgin Atlantic of North America, according to the vision described by its founder, Ted Shetzen. Until then, domestic competition is mainly provided by the charter companies like Air Transat, Canada 3000 and Royal Air. They're all good airlines, but on one of them (I won't say which) the service can be a trifle eccentric. On my last flight, the steward introduced the meal choice of chicken or beef with: "What would you like to risk tonight, sir?"