Davos Revealingly, the top jamboree takes place in a swish Swiss ski resort but always in the last week of low season, thus combining status with a commonsense approach to economics. It is at the apex of the opinion-forming circuit, combining the presence of world leaders (who are paid handsomely to attend) with the leaders of large corporations (who pay handsomely to rub shoulders with the great).
There is a high bullshit factor about the posturing in some of the public sessions, but there is little doubt about the calibre of the deals done over someone else's champagne. Davos can lay claim to having been first to put the transformation of the post-Communist economies of Eastern Europe under the magnifying glass. And on globalisation of the world economy, Davos did more than the G7 meetings every year to force the realisation that economies are truly interdependent. "The most invaluable part is that people get to know each other personally," said one regular participant. "When you have to make a judgement about what a country will do, it is extremely helpful to know the individual who will take the decision."
Konigswinter Started in the late 1940s in the home of a pro-British German industrialist, in theory this conference deals simply with Anglo-German relations. Its participants are less high-profile, but its mix of senior politicians, civil servants, bankers, academics and journalists has given it a wider status. It is particularly important in terms of defence. "It's very much of the cognoscenti, replete with acronymns and abbreviations," said one regular. "An acquired taste."
But it is credited with having created the feeling that some enlargement of Nato had to take place. Konigswinter also reveals one of the other key features of such gatherings: the importance of shared strolls in the countryside. It was on one such hike that David Steel and Shirley Williams forged the essential principles of the SDP/ Liberal alliance.
Aspen At the Aspen Institute, in a 1950s Bauhaus-style building in the glitzy Colorado ski resort, US and other English-speaking academics and policy-makers gather with politicians in week-long seminars. "It has a much lower bullshit factor than Davos," said one former participant. "People sit around in jumpers before log fires. It's all very informal."
The institute runs three or four seminars simultaneously on a variety of subjects, with 30-odd particpants in each. Its main concern is with US matters and policy options. The mood is serious and earnest and those invited are authorities in their fields.
Aspen regulars through the 1980s are now serving in the Clinton administration - which points to one of the great shortcomings of the conference phenomenon. Those who shine there do so because of intellectual excellence, which means asking the right questions. That was fine until they got into power, when they found that asking the right questions was not enough.
Ditchley Park At the top of the second division is this 18th-century country house near Blenheim Palace in Oxfordshire. It holds 15 conferences a year in the style of weekend house parties, with walks round the lake, cider for lunch and decent wines in the evening. Those invited include the real great and the good - who come because discussion is under Chatham House rules, which forbid any attributed repetition - and top experts. "Academically, they are the most heavyweight, but often the participants are overburdened more with medals from their previous service than with new ideas," said one veteran. "It's a bit of a fading star."
Best of the Rest There are lots of top conferences for specialists - such as the one for central bankers at Jackson Hole, Wyoming, every August. Better to angle for an invitation to the Foreign Office's official conference centre at Wilton Park, a country house in West Sussex, where the food is not grand but participants can buy a house tie and meet the pick of those East Europeans thrust into positions of responsibilty since the collapse of Communism.
Failing that, the British American Project invites influential thirtysomethings to meet annually, alternating in the two countries. It aims to spot the next generation of leaders in Britain and the United States and bring them together.
And if you can't get invited to the conferences, why not start your own? That's what the owner of the Daily Telegraph, the Canadian magnate Conrad Black, did. He calls it the Hollinger Advisory Board and invites up to 300 people. On one memorable occasion Baroness Thatcher was invited to address the group. One Telegraph director, Lord Carrington, her former foreign secretary, then entertained the rest of the board by ostentatiously tapping the side of his head whenever the Iron Lady made a remark which he deemed ill-judged. Getting the invitation, it seems, may be an indicator of success, but it is not a guarantee.