If you don't like prepaid or need to keep your US phone # you can always get a US T-Mobile plan with a triband phone (free with a 12 month US plan) and use that all over Europe including Norway, BUT you'll be paying roaming charges of $.0.99 per minute incoming and outgoing. That's the second best thing.
http://www.t-mobile.com/Internationa..._RoamWorldwide
It does work as it uses T-Mobile's European network.