I couldn't be in China during the summer of 2010 and not have every single person I met ask me, "Have you been to the Shanghai Expo?" The short answer is yes. The long answer follows.
Shanghai World Exposition 2010 is a huge and hugely promoted event surpassing every previous World's Fair in size, with more than 190 nations represented. A reported 53 million people, most of them Chinese nationals, have already attended. Judging by the endless queues, it seemed like most of them were still there the day I visited.
Alas, like many things Chinese, this Expo seems a bit hastily assembled -- it's a jumble of pavilions with no central theme or even a clear physical focal point.