By Sir Matthew Pinsent
BBC Sport in Beijing
Everybody agrees that the Beijing Games have been spectacular.
What worries we had over pollution, weather, politics or drugs have been calmed by 16 days of Olympic sport.
If you've been on intergalactic travel for the last three years it will be a huge shock to you that Britain is up next in 2012.
If not, here are the lessons for London that the Brits can take home and mull over.
OPENING CEREMONY
The Chinese took the ceremony on to another level.
Classy, dramatic and impeccably choreographed, it will simply be impossible for Britain to match in London for reasons of money.
We wouldn't and shouldn't spend tens of millions on the opening three hours of the Games.
But we can inject lightness and humour which was almost totally absent from the Beijing opening ceremony.
The only laugh I had was over the team uniforms which as ever are a range from classic to catastrophic.
THE VENUES
The Beijing ones were iconic but again eye-wateringly pricey to build.
There are whispers that the London venues will be 'dramatic on a budget'.
Of course we have to get ours to come in on time and on budget and given our history in big buildings that's something we cannot rely on.
EMPTY SEATS
They have been a really big issue in China.
The corporate sponsors say it's not them not taking up their allocation, the tour groups say theirs are sold out and yet big expanses of the stadia have been devoid of passionate fans.
The irony is that domestic and international supporters are dying to get in.
The British cyclists' families struggled to get tickets to watch their own sons and daughters win medals, and yet sure enough even the velodrome had some spare seats.
It's a persistent problem with sports events and it shows even in China it's a tough one to solve.
RESTRICTIONS
If you can't blame the organisers for empty seats directly, their decision to block off the Olympic Green is a great pity.
If Olympic tickets are expensive and hard to get then allowing the public close to venues, even on the outside, is a thrill for the hosts.
Olympic Green is built to take vast hordes of spectators milling happily about letting the Olympic atmosphere sink in.
But the Chinese have blocked it off to all bar ticket holders.
The sight of Beijing residents standing at the fence taking photos of the Bird's Nest is heart-breaking. London must make the Stratford site as open as security will allow.
TRANSPORT
The bulk of the Olympic traffic falls to trains not the roads.
Here the underground is modern, air conditioned and relatively uncrowded.
Not three adjectives you'd use for the Northern Line in August to be honest.
The planned "Javelin" trains from St Pancras to the Olympic site in the East End must be excellent.
SECURITY
The answer here has been people and capacity. Every security cordon is well staffed 24 hours a day.
There is even an airport scanner at the hotel I am in. As a journalist I pass through it in the lobby and on to an air conditioned bus for a 20-minute transfer to the media centre.
Goodness knows how many times that has been replicated across Beijing.
In London, security arguably will be even more important than here, but I've been here three weeks and the total time in the queues here equals about three flights through Terminal 1 at Heathrow.
VOLUNTEERS
They are the lifeblood of every Games and they have been excellent here.
Lots of them, of course, and multilingual, open and courteous to boot.
The Manchester Commonwealth Games had throngs of great volunteers and the London Games are going to need about twice as many.
PARKS
London has dozens of them and we also do big screen sport well in the UK.
The equation is pretty easy - good sport, big screen, thousands of spectators plus a few cold beers.
They tried it here in Beijing but they didn't go down well, for whatever reason the average city resident preferred their own front room.
THE HOME TEAM
China have performed beyond all expectations, and the expectations were pretty big to begin with.
Team GB have had a huge medal haul, too - cycling, swimming, sailing and rowing all covering themselves in gold and glory.
But the expectations will be that we go even better in four years time.
After 19 golds and 47 medals in total that is a very, very high standard. But my sentiments are the same whether it's the home team or the host nation - "Come on Great Britain!".
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