He'll probably have to use the hotel internet for Skype. Skype is a voice over internet service that relies on having a good solid internet connection with the host country doesn't block. China periodically blocks Skype and I cannot tell you what their position is this week.

You can buy an unlocked quadband GSM mobile and purchase a prepaid SIM card in China. The rub in China is that it is a regionalized market and that a Beijing SIM will be roaming in Shanghai, etc. The domestic roaming rates aren't awful, but they are real.

Another option is:

http://www.rebelfone.com/china_simcards.aspx?couId=38

They will rent you a contract Chinese SIM card for $1 a day. Incoming calls are $0.15 a minute. Outbound call to the US are $0.50. This approach is no hassle, but not the rock bottom price. If you are on a tour (which it sounds like you might be), it will avoid having to force the time in to get the SIM and get it registered.