Anyone (preferably Cingular/AT&T customers) have a clue as to whether a phone could be purchased in one state, and activated with a phone number in another? Reason I ask, is that I live in AZ, but will be in Portland (OR) next month. Since they have no sales tax, buying an iPhone there would save me about $48 or so in tax. But... If I couldn't get a 602/623 area code activating it there, then why bother, eh?