I will be going to Japan and China next month. As I don't want to activate the data roaming on my carrier due to the high charge, I am looking to buy local Sim Card with 3G data plan that is cheap and usable in both Japan and China.
Where and how I can buy them? I am carrying an iPhone 4.
I understand that I can buy Chinese SimCard 3G with data plan in China, but unfortunately with that SimCard comes with a lot of restrictions as to which site I can browse and which site I can't. Is there any other better alternative?