I am sure there is a limitless supply of pictures like this*, but I found this set particularly affecting because it resembled what I'd seen at other schools. This link, via a Chinese correspondent, is to a Chinese-language site that ran pictures of a Sunday sports day/fun fest at Beichuan Middle School the day before the earthquake. Beichuan was of course near the heart of the devastation, and presumably most of the people shown in these photos are lost. (See important update below.)
Here is a sample, apparently of a middle-school teacher competing with kids in a basketball-carrying stunt race:
And some of the kids taking a turn:
There are many, many more pictures of the sports day at the site -- followed by a few shots of bodies on the school yard after the earthquake. The descriptions (in Chinese) on the page talk about "Beichuan Middle School's Final Day of Smiles" etc. I include them because they are, again, true to the kind of thing I've seen in provincial China -- and different from what most Westerners imagine when they think of the country.
UPDATE: The man in the first photo is indeed a teacher, Tang Gaoping; the pictures are from his blog, which attracted wide interest in China after the earthquake. Then on Sunday, six days after the quake, it was confirmed that Tang and his students had gotten out of the rubble and were alive. Details in English here.
* Update on limitless supply of pictures: Roland Soong has posted 300 on his EastSouthWestNorth blog.