Norwegians are earthy and practical, Swedes are the nerds with engineering degrees, the joke is that it took a swede to notice that the norwegian toilet seat was useless. I'm caroling with some swedish family friends on sunday, I'll let you know if the joke's as bad as I assume it is.
I forgot to ask them about the joke, I had too much glog. And "Scandinavia and the World" explains their relationship so much better than I can. (It's accurate in most things, except for her false assumption that America still cares about anything happening in the UK or her commonwealth.)