It's actually really easy. Do everything in US dollars, or US traveller's cheques.

To bring money into the country - bring all of your money in US dollars or US traveller's cheques. If you are Canadian, I know of a few banks that you can use your Debit card internationally. You can also put money onto your visa and take it out when in China.

To get money out of China without the fee, just use the black market. It's a lot easier than it sounds, they are the guys hanging around outside the banks, and if you are having a hard time finding them, you can even ask the bank staff how to find them! The exchange rate should be about the same as the bank, and you don't need any documentation. There are money checking machines inside the bank, make sure that the guy you are changing money with shows you that it is authentic with those machines, or you can just watch him withdraw the US dollars from the teller.