The cheapest way to make international calls is with skype, if you have a laptop or PDA and have a data tariff (which has other uses, like poker

) then you can make international calls at local rates.
As far as a normal tariff goes, I recommend one of the cash back offers
http://www.e2save.com/contract-mobile-phone/Nokia-2310-Red-Price-Match/NOK2310RED by far the best deal (can't beat free!) for a normal contract, but no better for international calls unfortunately.