Even before the current anti-terrorism regulations at airports around the world went into effect, it seemed that fashion was preparing for the moment when "less is more" would become the watchword of the travel industry.

Turkish designer Fusun, for example, whose line sells out in cities from Beirut to Quebec, has a knit bottom that doubles as an evening dress. Her collection, which is composed almost entirely of knits that don’t wrinkle, caters to a travelling audience.

But clothes that travel well are not new among designers. What makes Fusun’s line different is that the items that espouse a jet-set-happy lifestyle not only suit multiple occasions but also have multiple uses.

A red multi-coloured flared skirt, with jacquard yoke shot through with subtle gold threads, for example, is casual enough for daytime; fitted with a gentle waistband that doubles as a bandeau, it becomes a cocktail dress.

Fusun, who spends a large chunk of her working life on a plane, says women should be able to go from flight to meeting uncrumpled. "If you can bring just one or two items that are structured, not sloppy and pack extremely well, why not?"

A similar philosophy is apparent over at Ports 1961, where Tia Cibani, creative director, has made a bubble skirt that appears avant-garde and trendy and then converts into a more conventional, conservative dress. Her clientele, young actresses such as Michelle Trachtenberg and socialites who once favoured the NY-London circuit and now favour the NY-London-Shanghai route, have to pack light. Cibani herself moves constantly between fabric sources in Italy, Ports 1961’s NY offices, and its factories in China; she knows for whom she designs

The reasons for the sudden obsession with one piece for all uses is pretty clear but, interestingly, it is possible that the battle to provide the one must-have travel garment actually began several years ago. In June 2003 the spotlight on baggage theft intensified after rap star Lil’ Kim reported that $250,000 worth of jewellery had been stolen from her Louis Vuitton bag at JFK.

The jewellery was later found in an airline employee locker room, and later that same week two baggage screeners were arrested in Miami for stealing from checked luggage. And hot on the heels of that news it was revealed that, earlier that year, a federal security screener in New York had been arrested for stealing thousands of dollars in cash from passengers while inspecting their belongings at an airport checkpoint.

No wonder frequent-flying actresses speak of wishing to avoid a Lil’ Kim situation. Thus the likes of Anne Heche, Angelina Jolie, Jennifer Aniston and Alyssa Milano these days favour convertible dresses such as the one made by Karanina: a wrinkle-free jersey number that rolls into a carry-on (even a 35cm x 45cm x 16cm one) and can be worn five completely distinct ways.

While other designers such as Rachel Pally have created items they call convertible dresses (Pally’s goes from a halter dress to a tube dress to a skirt), Karanina’s number goes from sundress to formal with a few changes in ties. The item is so versatile that it confused editors and buyers who first saw the dress presented on runways in three different ways and didn’t recognise the item as one and the same.

Popular at Le Bon Marché in Paris, Coco Ribbon in London, and Neiman Marcus, Henri Bendel and Nordstrom in the United States, the company cannot seem to keep the go-everywhere number in stock. The dress now comes in six fabrics including solid silk jersey, two-tone silk jersey, and black with a champagne inside, as well as 12 colour variations.

Now Karanina, headed by Kara Smith, is making a whole business out of do-everything clothing. "We designed a top that is also a wrap that can be tied 20 different ways; we have skirts that can also be dresses. About four or five of our items have multiple uses. There is a top version of the dress. There are tops with removable straps so they can be good for daytime or made more sexy."

Even more timely may be resort developer Bernt Kuhlmann’s scarf-with-pockets - a sort-of wearable carry-on. Kuhlmann, who spends 30 per cent of his time on aeroplanes (including travel to his summer residence in Nova Scotia or his current project, the Aman Giri in Utah), says: "Between flight delays, more baggage checks and now fumbling through security, I felt frustrated; I was wearing a jacket just to carry my travel documents. And it’s all about things coming off easily at security."

Called the Xubaz (pronounced shoe-baz) Functional Neckwear, Kuhlmann’s scarf stows a traveller’s money, iPod and keys. Kuhlmann hired former Ralph Lauren men’s wear designer Keith Lissner and the two made the scarf initially in both a lightweight all-weather, travel-synthetic material and a luxe hybrid that feels like kidskin, and in five colours. Arriving last month at stores where travellers shop, such as Flight 001 in New York, Fred Segal in LA and Tashia in London, the Xubaz will help prevent theft at the security checkpoint, Kuhlmann hopes.

"You hear all these anecdotes about people getting through the metal detector and their wallet is no longer in the security bucket, but what thief is going to think to grab your neckwear first?"

The Xubaz comes with clips that can attach to the wearer’s waistband so it stays in place during in-flight turbulence. And the scarf conveniently shields the wearer from that pesky overhead aircraft draught. But an added benefit comes from the fact that if coffee is spilt on the scarf, it will bead right off the fabric, which feels like silk but is dirt-resistant.

This autumn, Kuhlmann will add a new terrycloth Xubaz to the range, so that once on vacation, active types such as joggers will no longer have to load down their shorts with wallets and iPods.