Cell phone service is excellent in most parts of Asia, and especially China. Indeed, it is much more common to have cell phones in China than in the US, for example. Thus it is very affordable and practical to get your own cell phone service while traveling so that people can easily reach you, and so you can easily reach others. However, there are some things to keep in mind as detailed herein.
The first thing to understand is that whatever “global plan” your domestic cell phone company may offer to use your phone in other countries is USELESS.The phone company will charge you outrageous rates for “roaming” service. Thus unless you just want an emergency contact phone number, what you will want to do is purchase a cell phone account in the country in which you are traveling. The latter is typically pretty easy and can be done without any long term commitment, but rather on the basis of recharging the account with cash payments as you use up your minutes.
It is possible that you could use your ordinary phone, and simply switch the internal card which provides cell service - a small square card called the “Sim card”. However, there are several things to keep in mind to assess whether you will be able to use your own phone. Firstly, all phones are not all the same but rather each is hard wired to work with a specific type of cellular system. Most of the world uses a system called GSM (including China), and thus when traveling to those countries, your phone will only work if it is a GSM phone. The USA in particular uses various cellular systems, and GSM, while growing in use, is not nearly as dominant as elsewhere. So the first step in figuring out if your phone is useful while traveling, is to see if it is GSM. Also please note that GSM comes in different frequencies, and so you want a phone that is triband or quadband to cover all the relevant frequencies.
Secondly, if your phone actually is GSM, the next thing to verify is whether it is “unlocked”. In many countries, and especially the USA, cell phone companies sell your cell phones that are “locked” so that they will only work with their services. Such companies have different policies about whether or not they will unlock the phones - some will never do it, others require you have been their customer for a set number of months, and so forth.
If you can meet the first two criteria, then all you need to do is open up the phone and usually you will find the Sim card located under the battery. Take out the old one (keeping it for use when you return home), and put in the new Sim card that the foreign service provider gives to you. The phone should work right away.
It is possible to get email through Gmail, etc. on a China based cell phone service. We do not at present have details. If you want to bring your present phone and get email through your domestic service, please be appraised that Blackberry can be a great deal. Usually your cell phone service provider charges a set rate for the time you are gone to give you unlimited email access. However, if you have a “smart phone”, please note that typically that is very different - instead you are charged per useage, which if you are not careful can quickly become very expensive. Smartphones also allow you to access internet services and resources though wireless connection. Provided you find a free hotspot (hotel, etc) you will be able to read and send email for free.