There is an exhibition on in Oslo at the moment. It´s called "Take me to your leader" and is a jumble of art loosely related to space and aliens. Not a very good exhibition as a whole, but it still has some really good pieces. Here are some of them.
A small sized Darth with his light-sabre penetrating the complete collection of Harry Potter books...
Ilya Kabakovs masterpiece "The Man who Flew into Space from His Apartment"
two views of an cyborg alien by H.R. Giger
And, last but not least, the coolest item in the exhibition is really not an art object. It is a Lone Ranger Atomic Bomb ring from 1946. It´s said to actually hold some radioactive material.
I found the ad for the ring on the net (below)