Sounds like a lot of time on trains or other transport for a short visit. If you haven't toured Oslo before, you might consider staying there for 2 days or whatever you have. A nice little city and you already need to be there for your departing flight I enjoyed Bergen, perhaps a bit more than Oslo, as a cute, but smaller city. I did Norway in a Nutshell -- it is nice and pretty, but somehow expected more than the build-up. I'm glad I went, but i had more time--4 or 5 nights in Oslo, 1 night in Flamm, and 2 nights in Bergen.