Personally I just use a US layout with alt gr for æøå. The Norwegian layout is very awkward for C style languages(and the unix shell), I find. The US one feels more natural, which makes sense considering the modern US layout is very similar to the layout of the teletypes used at bell labs in the 70s.
Took a while to get used to it, but only a month or so to be just as fast as I was previously on the Norwegian one.