I am not absolutely sure with the "function" but seems like to me that we need a local Chinese as a guarantor. They record the detail of my Chinese friend based on Identity card. The SIM card registered to my friend's name and also my name.

The shop told us that one person is allowed to have maximum 5 numbers.

A manager at this China Mobile office on Renmin Zhong Lu told me they could register passport before 7pm without any problem: j.map.baidu.com/KVBx3
He also told me there's no reason why the Xiaoximen office couldn't do it.
For China Unicom, looks like you need to go to their office near the Panlong river j.map.baidu.com/C0Cx3

if muppets dont knwo how the answer will always be buxing

I just got a SIM without a 'Chinese Friend' today at the China Mobile on Renmen Xi Lu. I went in with my passport and got a ticket and had a new SIM for my iPhone 30 minutes later. I speak a little Chinese but they even had someone who spoke pretty good English there to help me out.

Thanks for the info. Seems Renmin lu is the place to go. According to what they said-(that xiao xi men should be able to do it) I guess it's just laziness and incompetence as per usual.

@Sarah: How much was the SIM?

@mPRin I paid RMB 50 and get a SIM Card. But I am not sure what package I am having in it (talk time, sms, data).