Cazza_fly, Norwegian has trice weekly flights from OSL to KEF. In case some of you didn't know: Norwegian's by far largerst hub and base you will find at OSL. Measured in available seats OSL is over 125% larger than ARN, the second largest hub and base. If you want to learn more about Norwegian, a good starting point would be the CAPA Norwegian report from Feb 2013:
Norwegian Air Shuttle: at a critical turning point | CAPA - Centre for Aviation
Not even Robin Hood can persuade Norwegian to fly to DSA.