Can North American cell phone work in China ?

(USA)

My American cell phone is locked by the carrier. I would like to get both cellular phone coverage and e-mail if possible when on my first trip to China in a month. I'm going to Shanghai (Cixi), Beijing and Guangzhou.

I have looked on China mobile phones site and see I can purchase a China SIM card and add airtime. What would be the price of purchasing a smartphone when in China, like a blackberry? Am I likely to be able to get my gmail email while in China??

An alternative is to get my phone unlocked while still in America, and then just input the SIM when I arrive China ? Having gmail access would be really helpfull whilst traveling in China.

Answer:
The easiest way is to call your American carrier, asking them to send you unlock code. As long as your current phone has bands GSM 900/1800 mhz. If it is currently tri or quad bands, it should be no problem.

Most major carriers have the responsibility and will do it for you, it's free. Some operators require you to be a customer for 6 months.
It is very simple to call them and tell them you are traveling overseas, you want your phone unlocked. Give them the serial number and EMI #, they will text or e-mail you a code, you enter code and unlock it. Even the iPhone you can go jailbroken now.