Hi Dave XT17000,
I am in Melbourne AU. going to Zhengzhou on the 23rd July. Yes Dave you do need a letter of invite from your friend if you are staying with her and family in there home.
If no letter of invite you must have a paid hotel booking letter.
That was the Chinese Consular in Melbourne ruling and also on the Australian Chinese Web Site.
http://melbourne.china-consulate.org/eng/hzqz/t57200.htm
Had no trouble getting my visa with my future wife letter of invite but they are only giving two months visa at the moment but you can extend in China
That was on the 28th June.

Also a note to anyone getting married from Australia you must have a signed Statutory Declaration as per the UK details. They do not ask for it on the Australian Chinese Web Site.
See http://www.mynanning.net/gettingmarriedinchina
This was my most costly document here in Australia:
Statutory Declaration You can do this yourself.
Notary to sign Statutory Declaration for you $55.00
Then to Department of Foreign Affairs and Trade stamp of authentication'$20.00
Then Chinese Consular authentication $30.00

Hope this helps Ray

Fantastic post - Worthwhile, meaningful and helpful - Thank you Ray - I have moved it into this Nanning Specific Information area.