Oslo Pinheads is 40 minutes with car outside oslo, closer to the airport. Currently they dont have open events, I could set you in contact with one of the guys there through facebook if you want. Else, as Axl mentions, Oslo Pinball Club is much more active and tomorrow it is a "repairing event", but with some playing of course. I can also set you in contact with one of my friends there, i cant attend tomorrow unfortunately.
Its only 10 minutes from the city centre with bus/car, so its quite easy.
How long are you staying here mulder2010 ?