Anyone know if there is a good commonly used Chinese OAuth provider? Or Japanese and Korean for that matter?
Of those mentioned in the answers, I think QQ would be your best bet. I have never seen anyone use Renren, but everyone seems to have a QQ number.
Another of those "everyone has it" apps is WeChat, which also provides OAuth: http://open.wechat.com/cgi-bin/newreadtemplate?t=overseas_op...
I agree that WeChat is more popular, though. Those who have both my QQ and WeChat contacts overwhelmingly go though WeChat.
I was looking into getting my app translated, but haven't even thought about OAuth providers.