quack - 10:22 pm on Jan 17, 2010 (gmt 0)

I've done some more reading and Google has done a better job lately at indicating what is 'unacceptable'. In their vernacular the term 'cloaking' is strictly black hat and they don't have a term for what is considered acceptable. In general though, using cookies or geographic locations to modify a page is acceptable but using IP addresses or identifying bots is not.