Norway in February...

Have come to my favorite resource for help! Hope you can provide it!

I am heading to Norway to take my 23 year old son to the Ice Climbing Festival. We will head to Oslo and spend a day there then he will go off to Rjukan to the festival. I would like to join him for a day. Has anyone been to Rjukan? is it worth me spending a night there?
We will join up again on Sunday and spend a few days around Norway. Any suggestions to what to do? Where to stay? Where to go?

Yes, I know it will be COLD in Norway :D

If either of you are drinkers, bring your duty free liquor. I would guess Norway is as $ as Sweden ($15 pint for generic vodka) Unsure about beer/wine prices in Norge but either one in a Stockholm bar is $10.
Sounds like could be a really novel trip!! Have you looked at tripadvisor.com? You can get fast answers--might already be a thread posted with what you need. Have fun and let us know how it was!