The New York Times has a long and detailed piece on Chinese manufacturing, as seen through the lens of Apple's decision to manufacture the iPhone there. The key issue may surprise many, as the NYT says that it's not simply the low cost of labor that drives companies' decisions. Instead, it's a combination of extreme speed and flexibility in ramping up new production lines, economies of scale, availability of mid-level engineers, and centralization of different plants that makes it radically cheaper and often more efficient to product gadgets overseas. The interlocking issues of supply chains, labor costs, and infrastructure likely means that these types of manufacturing jobs won't easily be moved to the US or other locations anytime soon.
In a key anecdote, it's revealed that the iPhone was originally designed with a plastic, not glass screen. Less than a month before it was unveiled, Steve Jobs demanded the switch, and the Chinese factory where the iPhone was made was able to switch systems and begin pumping out 10,000 iPhones per day with four days of receiving the new design from Apple's engineers.