Oslo to San Francisco that's quite a trip! I'm Danish and up in Seattle and we go to Copenhagen sometimes, so I know how it is.

I hope you have fun exploring San Francisco; it's a good city to have "the American Experience" when you come from Scandinavia. I don't know how much you will be able to get around, but if you have a chance, get out to Muir Woods in Marin County where the giant redwood trees are. Enjoy!