yes but it is a little different so they can censor the internet and monitor your text messages

Yeah you can. You can go into any mobile phone shop and ask them about a 3G "手机套餐". If you don't speak Chinese, I highly recommed bringing a Chinese friend along to help you interpret. You can choose from many difference packages (obviously with very varying price ranges) so it's important that you find a package that suits your needs. I've had friends tell me that China Unicom offers some of the best deals and they usually have better coverage in Beijing as well.