Aides say U.S. President Barack Obama really enjoys sightseeing breaks during the hectic schedules of his foreign trips, since they let him clear his head.

The blustery wind on the Great Wall on Wednesday may have helped as well, as Obama broke away from tour guides and walked alone for a few minutes to Badaling's third watchtower.

Mao said "Bu Dao Changcheng Fei Hao Han" which can mean "You aren't a great man until you've been to the Great Wall" but also implies "You aren't a good Chinese until you've been to the Great Wall."

Nixon said "I think you would have to conclude that this is a Great Wall and it had to be built by a great people."

And Obama?

"It's magical. It reminds you of the sweep of history and our time here on Earth is not that long and we better make the best of it."

He hadn't brought a camera, but he did seem reluctant to leave, instead posing for photos with American and Chinese ambassadors.

"It gives you a good perspective on a lot of the day to day things. They don't amount to much in the scope of history," Obama added.

Video credit: Jimmy Guan

China's Communist Party rarely admits mistakes, but Wen got kudos for facing up to his.

Wen, a trained geologist, mixed up his rock types while giving feedback to a Beijing middle school teacher, who had failed to encourage a student while Wen was sitting in on some classes this weekend.

Xinhua included the mistake when quoting his remarks.

Wen corrected the error and issued a public apology via Xinhua -- giving new meaning to the term "official correction."

But even the apology was not without some spin. The Beijing News said an alert reader had noticed  the error and alerted Xinhua, but the subsequent article by the state news agency said Wen himself had spotted the flub.

File photo: REUTERS/Jason Lee

As the plane slowly approached, the large Chinese and Venezuelan welcoming delegation began walking towards the red carpet, far, far away from us. But then a Venezuelan doubled back and gestered to the press. A break! Journalists sprinted towards the plane, dodging the airport security guards.
 
A furious argument ensued, as security guards tried to shove reporters back while maintaining some decorum with the embassy representatives. Chavez descended the stairs, grinning amidst the chaos. At the end of the carpet, he turned and began to talk to reporters, while the Chinese guards tried to edge him towards the cars. A few minutes of talking, with no end in sight, made them more impatient. Amid a new round of pushing, Chavez himself got bumped.

"Please," he said in English as he turned to the guards. "Soft, soft."

Photo caption: Venezuela's President Hugo Chavez speaks to the media upon his arrival at Beijing airport for his two-day visit to China, April 7, 2009. REUTERS/Jason Lee

A carbon fund named "Obama, future" could invest in increased forest coverage in another country and Obama himself could plant a tree there, Lin Hui said in an open letter, published on www.ditan360.com. Lin hopes that country will be China.

Lin's appeal is based on estimates by conservative U.S. think-tank, the Institute for Liberty, that people travelling to attend Tuesday's inauguration would generate 220,000 tonnes of carbon dioxide.

"Obama's presidency is a big opportunity. The whole world is pinning their hopes on him, even the greens, believing he'll be different than Bush," Lin told Reuters.

The website, run by a team of volunteers, contains news articles and information designed to educate Chinese about a low-carbon lifestyle.

The Chinese government, which has been active in encouraging Western firms to invest in carbon-offset projects in China, approved the website in April, Lin said.

Lin's posting in Chinese is illustrated with photos of Obama's "whistle-stop tour", his itinerary for Tuesday, and pictures from the inauguration of predecessor George W. Bush. He tried sending a copy of the open letter, which is in English, through Obama's public email address, "but I doubt he'll receive it."

Lin signed his congratulatory letter as "A Chinese citizen, also your friend in green career".

There were a lot of worries about the Beijing smog expressed by athletes and foreign journalists before the Games began. But for the last week, there has been a lovely salmon tinge to the clouds -- real clouds, not smog! -- in the evenings.

All this is due to Beijing having booted well over a million cars off the streets, idled construction sites, and closed the worst polluting factories for hundreds of kilometers while requiring the not-quite-so-bad plants to install and actually use emissions reducing equipment.

The weather also helped. After a hot, muggy start to the Games when a heavy fog bank sat smack over the city, some rain and a breeze have cleared things out.  The numbers of days where the air quality is rated excellent have soared.

Unfortunately, most of those measures are temporary, so our eyes and lungs may only be getting a short holiday while the Olympics and Paralympics are going on. You can live with normal Beijing air, in fact I trained for a marathon in it last year, but most people agree it's a lot more pleasant this way.

Still, there could be some long-lasting benefit, now that people see what the air could be like. Beijing's environmental officials have promised to step up monitoring of pollutants and continue imposing new measures to clean things up.

And in the grimy provincial towns that ring the capital, better industrial controls could also mean a better quality of life.

People like to talk about the "legacy" of Olympic Games. A cleaner Beijing would be a nice take-away from this year's.

PHOTO: Competitors jump during the men's quarterfinals run for the BMX cycling competition at the Beijing 2008 Olympic Games August 20, 2008. REUTERS/Jacky Naegelen

The Bird's Nest stadium, built for the Olympics, can seat 91,000 fans. The air flows through well, keeping it cool in the muggy Beijing summer. The seats are well-positioned, so the contestants can be seen easily. The screens are visible, the sound-system clear, the lighting strong but not harsh.

The Mianyang stadium, in Sichuan, is currently housing nearly 20,000 refugees. Every railing is covered in clothing, the floors covered in cardboard and quilts. The glassed-in second story helps shield old people and children from the rain. The screens are tuned to television coverage of the disaster and the PA system booms out the radio news.

Lucky Beijing, Unlucky Sichuan.

But the two stadiums have some things in common.

A small army of young volunteers works in each. Fresh faced volunteers in Beijing answered the call to help China's Olympics make a shining impression on the world. Masked volunteers in Mianyang answered the call to serve fellow Chinese in an hour of need.

Lines for snack food in Beijing's stadium are polite and orderly, in line with campaigns for "cultured queuing."

Lines for food in Mianyang are also polite and orderly, but a lot longer, as refugees show enormous patience despite hunger and grief.

Taxis pull over on the road outside the Bird's Nest, so that people can take photos of themselves in front of the Olympic icon.

Cars pull over on the road outside the Mianyang station, to drop off donations of clothing and water.

Maybe it was my imagination, but I thought the applause of the Beijing crowd got a little warmer when the blue-suited Sichuan contestants won.

Pictures of scenes from Mianyang Stadium by Jianan Yu, Bird's Nest by David Gray

"It didn't look like much in the daylight but it looks fantastic at night."     

He was right. The structure called the Water Cube glowed a deep, bubbly aquamarine, beckoning from across a construction zone.

Picking my way along the side of the highway in the dark, through a metal gate guarded by guards in thick padded overcoats, and down a rubble-strewn road on a frigid winter night, I could already imagine it all spruced up for a summer Olympics evening.  

My parents and I had come to the "Good Luck Beijing" swimming open -- the inauguration of the Water Cube, a unique structure that features "bubbles" of plastic fitted into a steel superstructure.

The pattern is like a squared-off insect eye, rather than bubble wrap.   We entered through a tent awning, complete with airport scanners that required men and women to stand in different lines.

Chaos ensued.

I sidestepped a young lady vigorously arguing her right to bring in three full-sized bags of potato chips, grabbed my bag, rescued my bemused parents from attendants waving metal detectors, and in we went.  

Inside is like a convention centre inside an exercise ball.

The pool areas were warm and humid, and the observation deck for looking at the swimmers in the practice pool was cool. [H2O]3 was embossed in the glass - the Water Cube.  

The crowd cheered when the races were close and when the Chinese swimmers were announced. But I felt bad for the athletes, swimming their hearts out in the silent clockwork of the heats.

It was a far cry from the summer swim meets back home, when we'd would hang over the edge of the pool, shivering in our sweatshirts and wet suits and screaming as loud as we could to cheer on our teammates.  

The five-day match was a chance to get the kinks out of the Water Cube. Only about half the seats were installed in the galleries, and the Beijing grime showed here and there on the bubbles' skin.

But the pools themselves looked clean and bright, and the attendants carefully tried out their English phrases on us.  

The defining moment of the evening was a video during a break in the competition. Filmed last August, one year before the Games, it had Chinese pop stars singing "we've prepared for so long," and then in English "We Are Ready."  

I looked around. My Dad had tears in his eyes.

 Pictures of Water Cube by (top) Claro Cortes IV/Reuters and (bottom) Jason Lee/Reuters  

I did this entirely legally. I want lots of guests to crash at my apartment in August, and see this huge moment for China. So when the first round of the ticket lottery opened, I filled out the online forms, met all the deadlines, and picked the maximum number of tickets -- mostly for semi-final events where I thought I would have a better shot.

The tickets aren't just for guests of course. I myself can't wait to sit in the stands for at least one competition, and soak up the excitement. But I didn't even bother to apply for the Opening Ceremony -- I knew I had no chance, and anyway, applicants were limited to one ticket only. Who wants to be all alone in a crowd?

I got about three-fifths of the events I wanted, or 17 tickets for six events. That puts me among only 5 percent of Olympics tickets applicants, according to a membership survey by the American Chamber of Commerce.

Most Chinese I've told say the decks were stacked in my favour. "Of course you got tickets, you're a foreigner" was the first reaction from my colleagues, taxi drivers, and anyone else I told.

An informal survey revealed many of them had given up halfway through the lottery process, which I also thought was a little daunting. Or they only applied for the opening and closing ceremonies. Or only popular weekend events. But still. Their reaction also shows how much Chinese citizens assume that the system will never work in their favour.

"What's the use? We Chinese have no human rights. It's the little things like this that really show that common people have no rights at all," said Mr. Zhang, a Buddhist taxi driver who misses the days of Chairman Mao, when I asked whether he had tried the online lottery system.    

I know where they are coming from. When I first got to China, in 1995, foreigners enjoyed a clearly separate and privileged position. One of the "privileges" was to pay double for airplane tickets, so I always took the train.

In train stations, my privilege really worked for me. People might wait in line for days, only to find that their window had no more tickets, but foreigners could always cut to the front of the line. Across the board, the pattern held -- foreigners usually paid more, but in the end we got a crack at the scarcest goods.

Fast forward 13 years, and most of the privileges of being foreign, versus being Chinese, have morphed into being wealthy versus not. It's pretty easy to get train tickets nowadays, if you book through an agency for a small fee, but the migrant workers still wait for days in line at the station.

As for the Olympics, people with Internet access, Visa credit cards or Bank of China accounts could buy tickets, as long as they had the patience to figure out the lottery system. The rest of the laobaixing or "old hundred surnames" -- the common folk -- get to watch it on TV.

Lucy Hornby reports for Reuters in Beijing.  

Picture of  man waiting in line to purchase tickets for Olympics in the ill-fated second round of sales (photo by David Gray). Migrant workers queue for train tickets in Shenzhen in 2004 (photo by a Reuters photographer).