There is an active bookcrossing community in Oslo. In addition there are some active bookcrossers around the country.
We have monthly meetups at the OSLOS-OBCZ situated at the Oslo Central Station (OsloS), LaBaguette, second Thursday of the month at 5 pm. Information about the meetups is posted in the Scandinavian BookCrossing Forum: http://www.bookcrossing.com/forum/31. We also arrange extra meetups when guests are coming to town. Please ask us posting a thread in the Scandinavian Forum (you can write in English there if you don’t know any Scandinavian languages), and we will answer if we are available.
You can drop by any time in the opening hours of La Baguette to leave or get books from the BookCrossing bookshelf there. Normally there are books in several different languages in the bookshelf.
The photo at the top of this post shows the University of Oslo at night.