You can use some newer Verizon phones internationally, but you're better off getting a GSM phone.

I see you posted this a while ago - what phone did you end up getting?

Hi There,
I am new to cell phone. I have a very old (6 yrs old?) Sony Ericsson phone with ATT pay-as-you-go plan. I am thinking to buy a smartphone and use it with my existing pay-as-you-go plan. I will go to China for business next month for about 3 weeks. I also want to use it in here with a local SIM card(?). I am thinking about buy an used smart phone with Android OS on craigslist. But I don't know which one is the right one to buy and I don't know if phone used for Verizon can be unlocked for my use? I have heard ATT and Verizon are using different technologies. I am in Boston MA. thanks,