I'm living in Thailand but only am here on a tourist visa. I need to buy a phone and service. I will be traveling on business 60% of the time or more and need to be able to use the phone in Korea, China, India, the US etc etc. I wonder which phone service offers the best rates?

My wife is a Thai citizen and she will purchase the phone and service for me.

I need some help here. There must be many Thailand residents that travel abroad for work and need to use their Thailand based mobile phones when traveling. Please advise which company is best, AIS, 12 call etc.

Also, do Blackberry phones work here in Asia?