Held each year in Qinghai province, the Yushu Horse Festival features some amazing trick riding, mounted games and horse racing.
Check out the nice shots by Dan Fohrman on flickr. These really capture the energy and skill of the horses and riders, as well as the beautiful, colorful costumes and tack. jon.a on flickr offers this nice close-up of a horse, too, where you can really see the woven bridle.
This video has a very brief but cool segment showing the scarf race - where riders hang sideways off their galloping horses to grab scarves off the ground - and the mounted shooting competition. Unfortunately the video is 10 minutes long and the horse part starts around minute 9, so I didn't embed it here.
This event is not without controversy, due to the ongoing tensions between ethnic Tibetans who make up the large part of the population and the Chinese government. The area is being heavily promoted as a tour destination, and the remote mountain town is growing rapidly.