Six billionaires came to the surprise 60th birthday party that Conrad Black gave for his wife. So did Henry Kissinger, Barry Humphries, Anna Wintour and six dozen other big names. The food was sublime, as was the wine, which cost $62,869.57. Black paid $20,000 of that and put the rest on expenses.

I've been devouring the details of Barbara Amiel's party that have emerged during her husband's trial. Schadenfreude feels good, but so does disapproval, and thinking about that party makes me wallow in it.

I disapprove of surprise birthday parties - I've told my husband I will divorce him if he ever throws one for me. I also disapprove of talking to famous people. Being in the same room as them can be nice as the reflected glamour is vaguely exciting, but talking to them for any length of time isn't.

They are too self-centred, too tired and too scared of saying anything interesting lest it get out. I also disapprove of the over-fancy amuse-bouches served with the champagne. Such handled food makes me long for a packet of Hula Hoops.

As for the "fine calligraphy" in which the menus are written, that is downright vulgar.

The one thing that I don't necessarily disapprove of about the party is the big thing: that Black put two-thirds of the bill on expenses. The only excuse for holding such a dreadful occasion is that it served a business function. If it did - and that is what the court must decide - then getting the company to pay for some of it seems not unreasonable.

More interesting than the question of who should pick up the bill is why one would want to have business contacts at a birthday party at all.

Yet, in this, Black is not alone: you don't need to be as rich or as beastly as him to hijack private events and turn them into schmoozing business occasions. You simply need to have a particularly naked sort of ambition. Tests have shown that schmoozing can work. It worked brilliantly for the earlier part of Black's career and I know other people who are using it to great effect now.

Not long ago, I went to a birthday party given by an acquaintance. I was easily the most unimportant person in the room: the man had invited the board of his company as well as anyone else he could think of.

I was grumpy on the way home: what a dreary party, I said. And how pathetic, doesn't the man have any friends? Six months later, he was promoted to the job of his dreams.

To pull off this sort of schmoozing isn't easy. You need to be shameless enough to ask hugely successful people to your party, but you also need to sound alluring enough to get them to turn up.

A friend in advertising was recently invited by a pushy young colleague to the reception at his wedding. He boasted that the biggest names in the industry would be there, but when my friend turned up, she found herself in an opulent room in a Pall Mall club with 40 other people and a table on which a couple of hundred glasses of champagne waited with no one to drink them. The test of whether a party is a genuine celebration is not the absence of people more important than the host. It is the presence of people less important. Amiel's fails this test: the only people junior to Black were his nephew and a couple of Hollinger executives.

By contrast, the late Gay Firth, a friend and FT colleague, once gave a party to which she had invited a series of Tory grandees as well as people from the FT.

I remember watching her introduce the former chancellor of the exchequer and his wife to a shy, junior subeditor. Gay passed the test with flying colours: hers was clearly a private party and nice it was too.

If I get asked to a party that fails the test, coping strategies are sometimes needed. I've been given an interesting tip by a well-known City figure who goes to a lot of these things.

He reasons that if the party is a work do, then work rules apply. So when he finds himself next to someone grand who has underperformed conversationally, he offers some frank feedback. He may tell them that they should have tried a little harder to be congenial, or that they should have asked him some questions about himself.

I doubt if this will make these rude, grand guests behave better at the next Conrad Black-style event. But it may solve my City friend's problem. He may soon stop being invited.