Best option for world travelers and their cell phones?

Best option for world travelers and their cell phones?


Ok, from my research, there doesn't seem to be one good solution to this topic.


I have a tri-band phone (with a current Beijing CHINA UNICOM sim card). In Beijing, it's cheap to use. I wonder how it would operate in Shanghai, Hong Kong, or Taipei?


If I'm staying in these places for 1-2 months each, is it worth buying SIM card after SIM card in each place? Or is using the Beijing SIM card all the way the better option (of course, it would be more expensive)? But, what can I do here?


My second question is when I leave for America (after my trip in Asia comes to an end). I will, of course have the same phone (as it's TRI-band) (and probably a local SIM card from Asia). What would I do in America? And then in Mexico, after that?


What is the cheapest option for world travelers who only plan to stay somewhere for the short-term (a couple months but use frequent in/outband calling/and SMS messaging) and then move off again?

Some places it is cheap to get a local sim card. When I tried in Cambodia a couple of months ago I was told by service providers that only residents could get a card - there were locals who would lease me a card to use, but I was only there for a very short time, so I didn't bother. There are companies in the US that use sim cards, but coverage is mixed, and when I investigated it, overly expensive. There is a company called Tracphone in the US that can be relatively inexpensive (call time is expensive but there are no contracts) but you have to get their phone (I got one for free through a promotion). Mexico may have the same curse as the US.

If it's Unicom-Ru Yi Tong(http://www.chinaunicom.com.cn/brand/ryt/images/ryt0801012.gif) card, u can roam in SH. [local SH card saves $$$]


Ru Yi Tong Roaming charge:

Incoming

Y0.8(basic)+Y0.07/6 sec (long distance charge)

Outgoing

Local:Y0.8(basic)

long distance:Y0.8(basic)+Y0.07/6 sec

SMS:Same as BJ


HK & TW-- Buy a local card


HK-

Cheap calling:

Local Sim Card:0.12(day)/0.06(nite) or IDD SIM card:$0.25/min. [available at any 7-11]

Cheap SMS:intra(free) inter:$0.5 and int'l: $0.5-$2

http://www.peoples.com.hk/p_prepaid_kabayan_default_iso.jsp

I believe if you wish to take your beijing phone outside of mainland china (ie to HK or Taiwan) you need to subscribe to global roaming first. Like IDD, the phone company probably don't enable this by default and may ask for a deposit. Of course it will work in any part of the mainland as long as there is coverage. If it is pre-paid, make sure you buy all your top up cards in Beijing.


I use my Beijing phone (tri-band) in HK, Taiwan, Europe, Singapore, and USA frequently without any problems, but it is a post paid phone which I have to pay monthly at the bank.