I was in Italy recently with family members who are Iphoners. They pulled out the simm cards, then used Skype and a wifi connection to call home. It was just penny's a minute that way. Verizon's international rates for calling will hurt and a data plan is outright murderous. I don't know about Norway but in Italy, open wifi service is everywhere so calling home wasn't hard.
If you need cell service for calling each other over there, you can buy a prepaid simm card for a few euros that fits your phone. Verizon has to "unlock" your phone for this. If you have any old dual band cellphones laying around, they can be unlocked and used with the euro simm cards and you don't have to worry about losing a pricey Iphone. You can also buy a throw away cell over there and the simm card but that costs a bit more. Also, if your Verizon stores up there are like the ones here, they usually play dumb and just tell you call verizon.....
Sam