New York in the summer, as someone once observed, is a season that no true New Yorker will admit to having seen. For nine months out of the year, as far as New Yorkers are concerned, other cities only exist as also-ran backdrops in a news studio, fit to be Concorded to, perhaps, but hardly to be lingered in. Try to drag a New Yorker beyond city limits in October, and you will meet with staunch resistance. But come mid-May, even the most hardened addicts of Manhattan bootkick the habit and start tooting off anywhere else.

You will find them hiking across Bornean mountains, imbibing enviable water-borne parasites in Srinigar, or indulging in a spot of lavender- sniffing near Vence. When they rove nearer to hand, they unfailingly turn up in the Hamptons, a string of prim Yankee villages along Long Island's southern beaches, where modest, palatial clapboard houses contain servants from Jakarta, herb gardens wrenched from Kashmiri hillsides and fragrant chiffarobes smuggled out of the Cote d'Azur.

The microphone-using classes have berthed in Hampton towns for years now, exhausting local supplies of club soda and garden-party lanterns from May to September, and austere natives long ago abandoned any hope that the nattering newcomers would ever leave. Only somehow, suddenly, this July the unthinkable happened: the Hamptons ceased counting as Not New York.

In the Nineties - much as an attractive but noxious weed takes over a lawn - glossy vacation restaurants, boutiques and summer offices have supplanted the quiet groceries, whitewashed private beach clubs and blandly exorbitant steak-lobster-and-whiskey restaurants that formerly served the Hampton's tidy, poplin-shirted, towheaded-infant-rich population. Fax machines popped up in sunrooms. Women began dressing for lunch. Foundations and businesses started convening galas and meetings with gratifying results. And somehow, between the charity balls and wine-tastings, the can't-miss polo matches and art openings, the book-launch parties and "hot" restaurant reservations - not to mention the saturation of share-houses by paperback editors and bankers - horrified vacationers realised they had ended up in New York, in summer, after all.

By the end of the month, pointed cartoons in jaunty papers jabbed, "Connecticut's still Chekhov, but the Hamptons are Danielle Steel," and vacationers scrabbled furiously to secure less shameful summer addresses for August.

Luckily, one of the best things about Manhattan is that there are so many places that have nothing to do with Manhattan, places that are not even within New York State, that are regarded as mere outlying neighbourhoods, practically walking distance, begging to be visited on a sunny afternoon. Just as someone in Islington might contemplate an excursion to Fulham, the Manhattanite will say to himself, "I'll just pop up to the Adirondacks - after all, it's only a ten-hour journey, eight by car, one by speed- boat, half-an-hour by canoe and a half-hour trek through the woods to the "camp." The "camp" is Rockerfeller parlance for a rustic, two-storey establishment with guest houses, birch-railed terraces, docks and sailboats, and candlelight dinners shared with offspring of the signers of the Constitution.

New Yorkers who can't scare up enough references to gain entree to a "camp" resort to other quick outings. There's always Cape Cod, Nantucket and Martha's Vineyard in Massachusetts - only two hours away, if you can drive 300 miles an hour. Or, if you have more time to kill, there's Deer Island and Mount Desert in Maine, Lake Champlain in Vermont or Cape May in New Jersey. No place is too far away to be a reasonable substitute for the Hamptons.

Block Island, a delectable seven-mile-long stretch of honeysuckle, rolling hills, croquet lawns, rocky bluffs and antique lighthouses, has tried to head off marauding Manhattanites by co-ordinating ferry and train schedules, so that New York trains arrive at 9:05am, neatly missing the ferry which leaves at 9am. New Yorkers, undaunted, simply cosy up to their friends who have yachts, or else rise at 4am, catch a 5am train to an alternative city in Rhode Island, hire a taxi to a different ferry, and hit Block Island's Old Harbour by noon. The unresourceful, of course, can always fly - but flying without a passport is considered cheating.