So after a little searching I found a place just an hour from Kristiansand which offers rafting and riverboarding; problem is that I have never heard about it so I am a bit sceptical. My current plan is that try and go down there myself when the open for the season and try it out before inviting a bunch of GNOMErs to come rafting before/after GUADEC. On their homepage they have a video which makes the river seem reasonably nice, but it could be misleading and the river be much tamer than it seems in the video. At the end of the video there is some girls climbing in bikinis and watching it I was struck by the fact the gman never features such stuff in the climbing pictures he put up :)