The cool kids are moving away.

Let's put that more, er, diplomatically: British Ambassador Christopher Meyer and his wife, Catherine, are leaving Washington after a five-year tour of duty. They are arguably Britain's most popular export, hosts with the most, the exception to every stiff-Brit joke.

"They're fun," said Ken Duberstein. "They know how to laugh. They know how to party. If the Brits are supposed to be dour, Christopher and Catherine are cheeky."

And so a number of folks in this town are crying into their Pimm's. The official farewells began last night at the ambassador's residence with a dinner hosted by British Foreign Secretary Jack Straw. "The finest compliment I can pay to you is that I think you know how America ticks," Straw said in his toast to the Meyers.

They not only understand this country, they like it. "For sheer interest and stimulation, I've never had a posting to rival the United States," said Meyer.

Nor such an august roster of admirers. Last night's guests were an A-list mix of politics, media and business: presidential adviser Karl Rove, actor Rupert Everett, Labor Secretary Elaine Chao, Jim and Kate Lehrer, Harold Evans and Tina Brown, Supreme Court Justices Sandra Day O'Connor and Stephen Breyer, Federal Reserve Chairman Alan Greenspan and his wife, NBC News's Andrea Mitchell, and Gen. Richard Myers, chairman of the Joint Chiefs of Staff.

"It's a terrible loss," said Mitchell. "They are the most fun, the smartest and the wittiest couple. They have devoted fans in Washington -- always."

This was the first of three farewell parties at the embassy, in addition to the dozens of informal goodbyes hosted by friends.

"It's like reading a book and getting to the last chapter," said Catherine. "And you don't want to read it because then you'll be done with the book."

Every British ambassador enjoys a rarefied position in Washington, but the Meyers were especially popular because of their fresh, breezy style. They landed in Washington in the fall of 1997 -- just one day after their wedding -- and immediately established themselves as Embassy Row's dynamic duo. He was charming, funny and always wore loud red socks. She was playful, wildly stylish and outspoken. They hosted black-tie dinner-dances for haute Washington, full of clever quips and Motown funk. Tony Blair's Cool Britannia had arrived.

A few months later, Washington learned about the serious side of Catherine Meyer. The mother of two boys was locked in an international custody battle with her ex-husband in Germany. .

But despite intervention from high-profile Americans (including Presidents Clinton and Bush), the complexities and limitations of international treaties prevented Meyer from regaining custody; she has barely seen the boys, now 17 and 15, in the last nine years.

Meyer became a vocal advocate for missing and abducted children, founding PACT (Parents and Children Abducted Together) to give emotional and legal support to "left-behind parents." She also wrote a book about her personal experience, "They Are My Children, Too." When her oldest son turns 18 this year, he'll be free to see his mother whenever he wishes. "It's a woman instinct," she said. "I just feel things are going to change."

Now the Meyers are heading back to London, where Christopher is leaving the foreign service to become chairman of Britain's Press Complaints Commission. Last month, Catherine unloaded clothing, purses, shoes, jewelry and bric-a-brac at a garage sale, with the proceeds going to PACT. Their new life, she said, will be far less grand.

"The driver and the tennis courts are the two things I think I'll miss," she admitted with a laugh. In London, she'll continue heading the British arm of PACT and plans to enter a new field -- politics. "I got the bug," she said.

So begin the farewells. After Straw's long tribute, the ambassador rose to return the toast: "This is one of the rare moments when I feel at a loss for words."

"Not for long!" guests shouted in unison.

Meyer reviewed the highlights of his five years in Washington: "We started with Monica Lewinsky, and it looks like we're going to end with Saddam Hussein."

The Meyers officially leave at the end of next month. Then maybe, just maybe, they'll finally have time for a proper honeymoon.

"The honeymoon has been the United States," said Christopher.

"Is he the diplomat?" said Catherine, beaming.

Indeed.

Former national security adviser Samuel R. "Sandy" Berger has a word with British Ambassador Christopher Meyer and his wife, Catherine.Motion picture association President Jack Valenti, left, chats with Supreme Court Justice Stephen Breyer. At right, NBC News's Andrea Mitchell, CNN's Judy Woodruff, newspaper columnist Tina Brown and author Kati Marton.The State Department's Richard Haas, left, former national security adviser Brent Scowcroft and former U.N. ambassador Richard Holbrooke huddle.