Roaming Cell Phone Service?
 

Do I have to buy a sim for every major
city in China or do some of them roam??

A SIM like the Shenzhouxing will work anywhere in China. Might be a difference in rates calling from different areas, but it'll work.

Where do I find a Shenzhouxing sim....
anyplace I might find the rates?

Thanks

OK I've done a little research from what I read a "Shenzhouxing" is only good for China....I failed to mention
that I need to be able to call and
receive calls to/from the US. I
also found that I can get such a card
from China Mobile but I guess I'm still
looking for the right card....

You certainly can use the Shenzhou xing card for international calling, using a variety of methods.

With the fee-free Shenzhou xing ling yue zu ka your incoming calls cost ¥0.60 per minute. Outgoing local calls also cost ¥0.60 per minute.

Other outgoing calls cost the same basic rate plus a further surcharge of ¥0.07 per six seconds long-distance within China, ¥0.80/6 secs international, or ¥0.20/6 secs for Hong Kong, Macau, and Taiwan.

Receiving calls costs ¥0.60 per minute. All these charges go up by ¥0.20 per minute when you make or receive calls from outside the Beijing area (roaming), and there’s an additional ¥0.07/6 secs to receive calls. SIM cards can be just as easily topped up elsewhere in China, with the exception of awkward Zhejiang Province, where a trip to a local China Mobile main office is necessary. Note that mainland SIM cards of any kind will not work in Hong Kong or Macau, which have their own systems, nor anywhere overseas.

Long-distance calls can be redirected over IP by using the prefix 17950. Domestic long-distance becomes ¥0.90 per minute; Hong Kong, Macau, and Taiwan ¥2.1 per minute; US and Canada ¥3 per minute; the UK, New Zealand, Australia, much of Asia and most of Europe ¥4.2 per minute.

China Mobile also offers the oddly-named 12593 Cross-Ocean Express Service with further discounted international rates if you begin by dialling the prefix 12593: ¥0.80 to Hong Kong, Macau, and Taiwan: ¥1.20 to the USA and Canada; and ¥2 to Australia, New Zealand, the UK and most of Europe, but this only works when your Bejing-bought SIM card is used from Beijing.

Peter N-H