My night with Hollywood's new royalty

Gallery: Best dressed at the Oscars

Gallery: Worst dressed at the Oscars

Gallery: The Vanity Fair Oscar Party

Gallery: Brits at the Oscars

Video: Stars arrive on the red carpet

Video: Highlights from the ceremony

Video: Stars at Elton John's Oscars party

Video: Backstage reaction from the winners

Blog: Nick Curtis on the 'Oscarzzzz'

"It's not bad for an Essex girl, is it?" says Mirren, clutching her glinting statuette and beaming in a way the character she played in The Queen never could.

To my right, Penelope Cruz, whom every woman wants to dress like and every man in the room wants to, well, undress, nibbles a mini hamburger and trades commiserations with Kate Winslet, who is going home from an Academy Awards ceremony empty-handed for the fifth time.

The leading man of the night, Best Actor Forest Whitaker, who was born in LA gazes out over the lights of the Hollywood hills which burn like a billion bush fires, and tells best director, Martin Scorsese that the Oscars are "the best 24 hours in any city anywhere".

It's hard to disagree. Since I woke up yesterday morning I've breakfasted with Clive Owen and Cate Blanchett, sipped Absolut vodka cocktails and nibbled fillet mignon with Naomi Campbell and P Diddy, talked style with Giorgio Armani and watched James Blunt and Elton John perform a duet of Elton's hit, Tiny Dancer.

And here I am, still standing - just - giant dirty Martini in hand, surrounded by every A-list actor and actress I can think of at the Vanity Fair party. Oscars night bashes end at dawn in LA - around 4pm London time.

My 24 hours with Hollywood's party people started in typical LA fashion. "No one goes to the Oscars without a makeover," said Amy, my therapist, provided courtesy of Oscar.

It was 8am and the barbed-wire-thin 19-year-old from Santa Monica woke me up with a glass of liquid yoga, before taking me outside for some wood energy stretching.

"Lean on the tree and take your energy from the trunk, you'll need it tonight," she barked.

By the time I'd "got wood" and endured the teeth whitening, chemical peel, botox and the terrifying "all-over body hair manscaping programme", which involved plucking and combing my eyebrows into something called a "Now Brow", I emerged blinking into the watery morning sun, imagining that I had been transformed into Brad Pitt but, in fact, probably looking more like Chewbacca.

The first party in a day of one thousand parties started unfashionably early with brunch at the Four Seasons, the grande dame of Beverly Hills hotels, where most of the Oscar nominees stay.

I walked into the hotel, which rises like a giant caramel cake above the palmlined boulevards, and took my seat next to the bougainvillea-fringed terrace of the Windows Lounge.

On my left Clive Owen nibbled a So-Cal egg-white only omelette, while Cate Blanchett, ignoring LA's latest food fad - the green tea protein yoghurt diet - opted for the full English.

A morning champagne flute's distance away, Mark Wahlberg swapped pre-Oscars gossip with Stephen Frears, director of The Queen. When Kate Winslet walked in, Morgan Freeman mouthed "Good luck!"

There's no luck involved in looking good. Nominees plan their outfits to the very last stitch and at noon Giorgio Armani, the only man in Hollywood who was "wearing himself", walked through Windows Lounge on his way to the £5,000-a-night suites to put the final touches to Leonardo DiCaprio's two-button peak lapel tuxedo and singer Beyoncé's red Privé satin gown with lace-trim bustier.

My turn to be preened and primped. "You'll be in a Prada stretch-wool, three-button dinner suit, with cummerbund-style waist band, rib-weave Gucci shirt, Ralph Lauren black full-length tie and Zegna shoes," Amy announced proudly, fresh from the menswear department of Barney's department store near Rodeo Drive.

On the way to Elton John's party, I saw Armani again. "Ciao Bello!" he said as he climbed into his black Mercedes, followed by his entourage of shiny boys in black, each clasping a Blackberry to an ear as if taking instructions from some satellite fashion-people tracking service. Bello? Did I hear the Italian designer right? Ha! I've got the look.

At 5pm Elton John was standing at the head of the flash-mobbed red carpet at the Pacific Design Centre on the corner of Melrose Avenue and San Vicente in the heart of Beverly Hills.

Dressed in a Yohji Yamamoto black tuxedo with grey trousers and sporting a giant yellow diamond stud earring, he urged guests to "just have fun here tonight. Cheer, clap, jeer, even boo, if you like. And don't forget the outfits. You can cheer or boo those, too. I've already booed Meryl Streep's".

Inside, guests, who had paid several thousand pounds for the tickets - all sold in aid of the Elton John Aids Foundation - downed champagne cocktails, while swapping the names and addresses of plastic surgeons and ogling the latest multi-million dollar jewellery by Chopard. The Swiss firm sponsors the bash, ensuring that each year Elton wins the Oscar for Best Bling!

Victoria Beckham, wearing £3 million worth of Chopard diamonds and emeralds to offset her 1950s-style cream dress by Tunisian-born designer Azzedine Alaia, wafted past on her way to "mwah-mwah" Sharon Stone and Keifer Sutherland.

At least I think it was her. She's so tiny she looks like one of those cardboard cut-outs of the stars that are placed on the seats in the Kodak Theatre before the stars themselves arrive.

More than half of Elton John's guests were British and the night started badly. Sacha Baron Cohen and "Borat" adaptor Dan Mazer and Peter Morgan, writer of The Queen, had all lost out in the awards, followed by Kate Winslet, Judi Dench, Stephen Frears, United 93 director, Paul Greengrass, and veteran actor Peter O'Toole.

But, thankfully, the one Briton all of Hollywood was talking about got it right. When Capote star Philip Seymour Hoffman paused before announcing the Best Actress award, the room fell silent.

Then a Saturday-afternoon-on-the-terraces cheer went up when Mirren's victory was announced. "Easy! Easy!" came the chant from one table.

After dinner, as Elton took to the stage with Blunt and the party turned into an impromptu concert, I took to the road.

It is a few blocks' ride from the Pacific Design Centre to Mortons on the corner of Robertson and Melrose but, thanks to limo gridlock, the curse of Oscars Night, it took almost half an hour to get there.

While Will Smith entertains the press on the red carpet for a full 20 minutes, Oscar host Ellen DeGeneres sweeps in - having changed into yet another trouser suit - with Portia Di Rossi on her immaculately-tailored arm. A smart sartorial-move. Jessica Biel has a polite grin fixed to her face, and spends the evening pointing it at the various apologetic oafs who keep standing on the hem of her hot pink Oscar De La Renta frock.

Inside the flower-decked rooms, guests queued up to toast Mirren, who was celebrating with her director husband, Taylor Hackford, and the British cast, producers and director of The Queen.

"I said right at the beginning that you'd win it," DeGeneres declared as she hugged Mirren hello.

Oprah Winfrey grasped Mirren's statuette and said: "That's a hell of a gold star."

Minnie Driver gushed: "You're bloody fantastic. You're everything that's great about Britain. God, I mean, you haven't even changed you haircut in 30 years, you carry your handbag around like the Queen, and you're still winning Oscars. You should be an ambassador."

As the night went on, the Brits, who drink more and behave more raucously than the Americans, began to dominate-proceedings.

The British team behind The Queen went on a Veuve Cliquot bender with the gang which made the The Last King of Scotland. Honorary Brit Madonna and husband Guy Richie threw themselves into the throng.

Only Queen Latifah, wearing a green silk wrap dress, gave them a run for their money, by dancing with her co-host at the awards, John Travolta, before she and hip-hop impresario, Damon Dash, headed back the bungalows at the Chateau Marmont hotel for an impromptu after party.

As you read this, the Brit pack will be high up in the Hollywood hill's in billionaire music producer, Phil Spector's house.

There will be time for just one last glass of champagne, before the party is finally over and they head back in their limousines to their hotel beds to sleep.

It is more than 20 years since Chariots of Fire Oscar-winning director Colin Welland told Hollywood's aristocracy: "The Brits are coming." Last night, at the 79th Annual Academy Awards, it felt like we had finally arrived.