I'm not used to speaking from such an elevated height since I left office," Bill Clinton says from the podium onstage. "The air's a little thin up here." But every gulp of air is rarefied inside London's Marlborough House, where 1,200 money managers, moguls, and movers have each paid some $20,000 in support of ARK (Absolute Return for Kids), an innovative U.K.-based children's charity. ARK's chairman and social turbine is Arpad "Arki" Busson, the 44-year-old Swiss financier once romantically attached to Elle Macpherson, and tonight he has tapped his Rolodex to lure everyone from Nat Rothschild and Jemima Khan to one-name wonders Valentino and Madonna. Maybe it's them; or maybe it's the endless, bulbous bottles of Ruinart Brut; or maybe it's the women with violins who are harnessed — in a gravity-defying arrangement — to chairs atop towering topiaries, 30 feet in the air. Or maybe it's the fact that the former leader of the free world has just announced his partnership with ARK, but there's something wildly benevolent afoot. By night's end, ARK will have raised practically $53 million, smashing Britain's charity-dinner record.

Of course, throwing a conspicuously consumptive charity event can be fraught — especially in England, which doesn't share the American tradition of social mobility through philanthropy. (Donations aren't as easily tax deductible.) You want a party that will inspire people to buy tickets but not seem so indulgent and fall-of-the-empire that donors fear their money is all being spent on bubbly. Busson can pull it off because corporate sponsors helped underwrite the event, and, ingeniously, he runs — and markets — ARK as a charity that uses business principles (accountability, long-term strategy) for altruistic returns (education, child care, anti-HIV/AIDS programs). In other words, it's a sound investment. "ARK is a conduit for the hedge fund industry," Busson tells me. "We're a group of guys who got together and built this machine. But what I'm most proud of are our actual programs on the ground."

Efficient as ARK may be, it can also be jolly good fun. During the dinner of Kobe beef carpaccio and Cornish sea bass fillet, Clinton's table becomes the center of gravity. Busson, naturally, is seated to Clinton's right. To the former president's left is Crown Prince Pavlos of Greece, and then around the table are Macpherson (tending to her and Busson's two young sons), Elizabeth Hurley, photographers David Bailey and Johnny Pigozzi, Christiane Amanpour, Lord Edward Spencer-Churchill, Countess Debbie Bismarck, Crown Princess Marie-Chantal (Pavlos's wife), Tom Ford, and Madonna. Were that not entertainment enough, a ballet dancer in a skintight bodysuit climbs into a giant basin in the middle of the room, and, as plumes of water shoot down from cannons in the ceiling — kind of like an upside-down Bellagio water show — she begins a provocative arabesque. Perhaps looking for flexibility tips, yoga devotee and caustic capitalist Dan Loeb taps my shoulder and asks me to move over so that he, too, can take in the performance. Loeb is just one of many Yanks riding the transatlantic charity circuit; money manager and social swell Todd Meister mentions that he was at the Robin Hood Foundation's bash in New York the week before, which raised a similarly eye-popping $72 million. "But this one is huge, especially for Britain," Meister tells me. "Arki's got everyone here, even Elle." (Men still can't seem to get their minds off her.)

Up next: the auction. Haven't you always wanted to have that dinner with Mikhail Gorbachev? Or bond with Daniel Craig on the set of the next 007 movie? Those are just two of the lots on the auction block — and they end up going for $320,000 and $380,000, respectively. "It's a free world, but there are some very rich people in it," declares Harry Dalmeny of Sotheby's. "Does anyone want to take on the Material Girl?" he asks after Madonna bids $280,000 for a print of Horst's 1939 Mainbocher corset photograph. "Harry, have you filled out your pledge card yet?" Her Madgesty says, holding up a form. "This one's a little wrinkled because it's been under Bob Geldof's bum."