Chinese Visa Renewal for US Passport

Hello,

My current Chinese Visa expires on July 21, 2012. I am returning back to the States at the end of July, however, and would like to know what my options are. It appears that I could incur the fine for every day that I am in China past the date of expiration. What is that fee per day?

I would like to find a way to renew the Visa and get the same "one-year, 90 day multiple entry" Visa that I have right now. Is there any way to get that? Or would I have to return to the States to do so? Can it be done in China or Hong kong. I currently live in Guangzhou.

Please get back to me when you can. I appreciate your help.

Thanks,
Ryan