Hi Anne Marie,
When I created my account with Sony I looked up the zip and state from IKEA in Michigan (Sorry Sweden...) and there is no problem making purchases from Norway. I have also used the same method with Books on Board.
One thing though - I could not use my Mastercard (creditcard), but my VISA debetcard worked wonderfully. There are no currency-fee or tax, just a straight conversion from USD to NOK (Norw. Kroner). As an example I purchased last year Dan Brown's Lost Symbol for 9.99 USD which equals to 57,- NOK. Not bad considering at the time the hardcover in Norwegian bookstores wanted 399,- NOK for it.
Greetings from land of the midnight fun, eh, I mean the midnight sun...
ArcticBoy