Travel: Living in a world of their own: On the shortest day of the year, Simon Calder took the high road to Shetland and Frank Barrett took the low road to the Scillies, as Britain's extremities made ready for Christmas

The old woman in the newsagents on Tresco chortled at my obtuseness. 'How do we spend Christmas here? We spend it like they do everywhere else, I expect. We eat a lot and drink too much. How do you expect us to be spending it?'

But surely it must be different having Christmas on such a small island with so few people? She observed my pen hovering over my notebook. 'Why are you writing this down?' she asked sharply. For the Independent, I told her. 'We don't sell no Independents here - least-ways not in winter. I'll give you one guess what the best-selling paper here is. The Sun. Write that down,' she said, chortling again.

'Aye,' said a boy in oilskins, sitting in the shop drinking coffee, 'the Sun tells you all you need to know - and for only 20p.'

But on the Isles of Scilly ('Don't ever say the Scilly Isles,' I was warned, 'people on the islands get very cross about it'), it's surprising that the natives feel the need to read anything at all about what they disdainfully refer to as 'the mainland'. The islands may be a political part of Britain; spiritually, they are another world.

They may be less than 30 miles from the English coast, but when you consider that the nearest patch of mainland is Land's End, you realise that they are a remote spot that lies off a pretty remote coastline.

Although St Mary's, the main island, is just a 20-minute helicopter flight from Penzance, Scillonians rarely cross over. 'I get over there about twice a year - that's enough for me,' I was told by several people, as if Penzance were some exhausting and bewildering metropolis. 'There's not much over there - Safeways is about the only thing worth visiting.'

It took me more than six and a half hours to travel by train from Bath to Penzance, a journey complicated by the fact that flooding had closed the line between Taunton and Exeter. The coach company charged with the task of taking passengers between the two places had chosen a driver who didn't know the way. After completing three circuits of a roundabout near Homebase, he miserably appealed to his passengers: 'Does anyone know where Exeter station is? I hoped there would be a sign by now.' A white-haired old lady struggled to her feet in a panic: 'Oh yes - I want Exeter station please.' 'No dear,' said a kind passenger nearby, 'the driver just wants to know the way.' 'The driver wants us to tell him the way?' Quite.

But the helicopter flight from Penzance was fitting consolation: when it drops off the toe of Britain at Land's End and thrashes its way out over the Atlantic - crossing some of the wildest seas you are ever likely to encounter - the sensation is delectable.

The drive in from the air port also had its moments. I took my seat in the minibus to discover that the window frame next to my shoulder was thoroughly rusted away. 'You don't often see rust as bad as this inside a vehicle,' I observed to the driver. 'It's a problem all over the island,' was the reply.

One thing that isn't a problem all over the island is the MoT Test - it doesn't apply on the Scillies. Yet. Scillonians still harbour resentments about the imposition of income tax (1954) and the motor tax (1971). 'We shouldn't have to pay road tax - we hardly have any roads,' said the driver.

OUR BRIEF was to compare and contrast the pre-Christmas lives of Britain's two remotest spots, on the shortest day of the year, with me in the Isles of Scilly and Simon Calder in Shetland. Conceived in the lofty arrogance of London EC1, our Christmas shopping list was designed to point up the sophistication (or, rather, lack of it) down the respective high streets.

The wonder of St Mary's is not that its dozen shops sell so little, but that they offer so much. Despite having a potential regular clientele of no more than 2,000, the Co-op in Hugh Street can manage a bottle of Jacob's Creek red (at pounds 4.39). The Bourdeaux it's the family name) Wine Cellars has Ferrero Rocher chocolates, at pounds 2.75 - and such is the eclectic nature of Scillies retailing that the Wine Cellars' book department offered to order me a copy of Vikram Seth's A Suitable Boy in time for delivery by Christmas ('you'd better let me know by 4.30 - actually 4pm, to be on the safe side'). The lady at Banfields electrical shop (everything from Hoover bags to Nirvana tapes) said that Elton John's Duets CD was on order ('try tomorrow'). Douglas the Chemist even came up with a bottle of Paco Rabanne, albeit the common-or-garden variety, for pounds 16.95.

The pleasing thing about the shops is not so much what they sell but how they sell it. Most striking are the opening hours: from Monday to Friday they open from 9am to 12.15pm and from 1.30pm to 5.30pm - they have a lunch hour (remember lunch hours?). No late-night newsagents and grocers here; if you haven't bought what you want by 5.30pm, tough luck. And Sunday opening? Forget it.

The most important commodity the Scillies' shopkeepers have on offer is not what's on the shelves but the chitchat and gossip. They ache to pass the time of day. The lady at the post office was keen to bend my ear on the downgrading of the St Mary's Sorting Office; the woman at Rumbold's newsagents spoke at length on the controversial plan for the new Isles of Scilly Medical Centre. The wooden model displayed in her shop shows a building with a fire-station tower that would give the Prince of Wales the screaming habdabs (since the Scillies is part of the Prince's Duchy of Cornwall, his reaction to the plan is not insignificant).

As I wandered up and down the main street, I saw that St Mary's is the shopping centre that time forgot: it is locked in a pre-Sixties world that I thought had vanished with Janet and John books. When darkness fell and the delicate strands of seasonal lights were lit, Hugh Town began to resemble a

Dylan Thomas creation, somewhere between A Child's Christmas in Wales and the Llaregyb of Under Milk Wood; as I fumbled my way along the narrow road beside the sloeblack, slow, black, crowblack, fishingboat-bobbing sea, I half expected to bump into Captain Cat or the Reverend Eli Jenkins.

In the Mermaid public house (three-course pre-Christmas lunch, pounds 3.25), next to the harbour, a man was recounting his previous evening's activities. 'It was Scrabble Night, so I made a Christmas punch. It was bloody great. A bottle of Piat d'Or red wine, a bottle of vodka and a bottle of orange crush - and a bowl of ice.' Good? 'Well, I didn't half have a headache this morning]' A combination of literary endeavour and alcohol abuse that would surely have brought a glow to Dylan Thomas's heart.

I BUMPED into a Westcountry TV crew outside the Co-op and they kindly invited me to travel over to Tresco with them, where they were to film a report about the Christmas post on the Scillies. The star would be Irene Darling, the island's oldest inhabitant. Astonishingly, she is also the island's postwoman; aged 84, she is, says the Royal Mail, the oldest postie in Britain.

How long had she been doing the job? 'Twenty years or 30 years, I'm not sure.' She has a shed at the back of Tresco Post Office in which she has to sort all the letters before she can go on her rounds. 'Normally, it doesn't take very long, but before Christmas . . .' She peered at the address on one card. 'Appletree Cottage: that's a new one on me.'

I joined her on her round, which took her to the Tresco estate offices, where women were busy trimming and bundling the Grand Soleil d'Or narcissi. The Scillies' mild winter climate allows the flowers to bloom as early as October.

'The market is difficult, it's a struggle,' a man there told me.' We get about 50p a bunch for the flowers, and they sell for about pounds 2 on market stalls in London and Birmingham. It's getting harder.'

After her round, Irene happily tucked into a prawn sandwich in the public bar of the New Inn. As tactfully as I could, I suggested that being a postie might be hard work for someone of her years. 'No, I love it. I look forward to it. I would never give it up. I love meeting everybody; I know everything that's going on.'

Any scandals? 'I see all, hear all, and say nothing,' said Irene. A woman who joined us for a drink admitted that there were steamy stories to be told, but declined to elaborate. I told her I had heard rumours of wild parties on Tresco. 'New Year's Eve is the main party of the year on the island. Everybody wears fancy dress. The whole island comes, including the visitors - it's a big do. Quite often I've been walking home over the hill afterwards at 4.30 in the morning. Wonderful.'

Certainly nobody out late at night has to worry about their safety on the Scillies. Irene cannot recall the last crime on the island. 'I don't think there's ever been any on Tresco - we never see the police here.'

On St Mary's, the situation seems the same. People leave their bikes in the street, unlocked. 'Nobody locks up anything: bikes, their cars, their houses. We live dangerously,' the St Mary's librarian told me. Had there ever been a murder? 'There was a murder 15 years ago. It involved a gypsy and his son. It had nothing to do with the islands, really.'

Strange then that the novels in the library which use the Scillies as a setting almost all involve murder. What books do Scillonians like? 'Dick Francis, Jeffrey Archer, Richard Goddard . . .' Richard Goddard? 'Oh, yes, he's very good. Perhaps the most popular book at the moment is Alan Clark's diaries. Interestingly, I haven't had one request for Margaret Thatcher's memoirs - not one.'

THE SCILLIES weather was typically British, defying all expectations. On the shortest day of the year, and theoretically the middle of the bleak midwinter, the sun shone gloriously until it was about to set. But, as I walked up the hill to Star Castle to watch it go down over the Atlantic, the weather began to change. It was clear a mighty storm was approaching from the north-west: black clouds gathered and the sea whipped up, crashing against the offshore rocks in massive white sheets.

The sun quickly changed colour, the sky went a sickly yellow. From the foaming water that lies between St Mary's and Tresco emerged the thickest rainbow I've ever seen: it seemed solid enough to shin up. Everything looked strange. Far out at sea I could see the Bishop Rock lighthouse, a thin black factory chimney incongruously rising from the angry sea. Behind me rattled a huge illuminated Christmas star fastened to the castle wall. Below were the little Trumpton buildings of Hugh Town. And now the wind roared and the rain lashed. For a moment, the group of islands that stand on the fringe of Britain seemed to be only clinging to the edge of the real world.

(Photograph, table and map omitted)