SMS service is cheap.

Mobile roaming there is very expensive. If you are making a local call, you'd better buy a local mobile phone card. I don't know much about America, but I should have a phone card with a sum of money in it, which can be used in my mobile phone. It's best to contact China by SMS. Global SMS is around 1 yuan. It's cheap for the other party to call you back from China. If you don't want to use your mobile phone, you can find a public phone and use a long-distance phone card. Or find a network to Skype back and forth, see if it is convenient or not.

Of course, I'm a student. There's nothing urgent. I usually do this. If I come into contact with business, I think it's better to save money without delaying things:-)