Simon Calder: The Man Who Pays His Way

Mobile telephones that are safe on the west side of the Atlantic, potentially lethal on the east; a contaminated water risk threatening Australian aircraft; and seats from A to B that are bookable only at B. These are some of 21st-century travel's great unexplained phenomena, and as the summer surge begins, I urge you to look out for more.

Anyone who has taken a US domestic flight recently will be aware of an event that takes place seconds after landing. Half the passengers reach into their pockets or bags for their mobile phones, and start making calls. It is standard practice for travellers to be allowed to use mobile telephones while their aircraft taxis from the runway to the gate. "We know our customers are keen to get on with business or check in with family and friends when they land," says David Neeleman, the boss of JetBlue. "So we're giving them a few extra minutes to talk as they taxi to the gate."

Yet on this side of the Atlantic, air travel and telephones do not mix - even though the telephones and the aircraft (narrow-bodied Airbuses) are the same. On British Airways, passengers are allowed to switch on mobiles once the plane has reached the gate and the seatbelt sign has been switched off. But it is apparently too risky for travellers on easyJet and many other airlines to use them until "well inside the terminal building".

ON VIRGIN Blue flights, the danger to travellers is "tap water, which may be contaminated". Sir Richard Branson's low-cost Australian airline, Virgin Blue, refuses to serve ordinary water on its flights within Australia. Instead, passengers are offered "organic" water at A$2 (?0.80) a shot.

Aircraft have clean freshwater tanks that are replenished before each flight. Airlines routinely supply paper cups to allow passengers to drink from the fountains outside each lavatory. On long flights, drinking water is arguably the single most important activity to attenuate the effects of air travel. Virgin Blue knows this, and urges passengers to drink plenty of fluids in the pre-flight briefing. When Alison Lansley of Sydney was flying to Cairns - a three-hour trip - she had the temerity to ask for a glass of water.

"I was rather taken aback to be told that I had to pay $2 for a bottle of 'organic' water. When I countered that I had flown with Virgin Blue recently to Melbourne and been given free water without question she said this must have been a very special day and refused to be moved."

Leaving aside the definition of "organic" water, how can Virgin Blue justify this policy? That's what Ms Lansley asked the airline. And you deserve to see the reply in full: "Although serving free water may be seen as gesture of good service and a requirement for good health, airlines around the world are steering away from this due to safety concerns with the tampering of unsealed bottles and tap water, which may be contaminated. As a duty of care to our travelling guests, we feel that water should be of an international standard with sealed bottles. This, of course, comes with an expense to the airline and is passed onto the traveller."

That response contains interesting implications: that any airline (such as Virgin Atlantic) still providing tap water is putting passengers at risk; and that Australia's water supply is not "of an international standard", whatever that is.

VIRGIN TRAINS have improved remarkably in the past decade, but Matt Green from Manchester berates the nonsensical booking system. His problem: he bought an open-dated ticket from Manchester to London on Virgin Trains. The southbound journey was fine. But when he called the company to book a seat from London to Manchester, he was told it was impossible - he could only book the seat at the station where he bought the ticket - Manchester Piccadilly.

In other words, the only way to guarantee a seat from A to B is to book it at B. "Can you see the irony in that?" he asks. "If I am at my destination, I then need to take the return journey to book a seat for that very journey."

MAN OF MYSTERY

Mistaken identity is a constant problem in travel. For example, the organisers of the 2012 Olympics face an uphill battle informing visitors that the only connection between the Midlands town basking in Shakespeare links, and the wasteland in east London on which the main Olympic venues are to be constructed, is the name: Stratford.

I, too, am used to strangers mistaking my identity. "Excuse me, mate, but are you...?" I hear those words fairly frequently, and find them strangely comforting. The last few times have been on a train in Hampshire, a pub in London and, last weekend, the Piazza Amfiteatro in Lucca, Italy.

It is a cheering phrase because on each of those encounters, the question ends "...Louis Theroux?" Theroux is a talented TV presenter, and friend of Neil and Christine Hamilton and Anne Widdecombe, as seen in his excellent TV series Louis Meets... He is also the son of the travel writer Paul Theroux. And best of all, he was born 15 years after me. As the saying goes: when you look your passport photograph, it's time to go home. But when you look like Louis Theroux's passport photo, it's probably safe to keep travelling for a while.