The iPhone comes with the default system locale setting to en_US, to setup another locale for the system (eg, zh_CN), edit the following property list file:
/var/root/Library/Preferences/.GlobalPreferences.plist
Change ‘AppleLocale’ string to zh_CN, then move the zh_CN to the first place in the ‘AppleLanguages’ array.
Reboot iPhone, the iPhone will default to zh_CN.
To make a localized version of application, simply copy its English.lproj to zh_CN.lproj, and translate the .strings into Chinese.

One Comment
Dear George,
Can you please help us install NES for iphone 1.1.3. using the toolchain, or another method, I think the whole community will be grateful, Jonathan alias nervegas explanation does not help at all. May be some one like you can give a clear picture. I have already explored all the possibilities I can searching the net. Please do us this favor
Thank you for the blog.