Today I went to Roppongi Hills to check out the French Window exhibit in the Mori Tower. A ticket had been generously mailed to me by a friend I met here on the subway, which let me see not only the exhibit, but let me into the planetarium and on the very top of the building (the whole museum complex was on the 52nd-55th floor of the tower!)
The French Window exhibit was very strong - they had some of Duchamp's readymades, including one of his (in)famous R. Mutt urinals. I also particularly enjoyed the work of Laurent Grasso, Claude Closky, Cyprian Gaillard, and Saadine Afif.
The Planetarium was more a series of installations about the universe. By far, my favorite was the room modelled to resemble a 1000 light year big section of the universe. The stars, little lights hung from strings, were positioned precisely as they are in space all around the room. You could stand in the middle of the room and view everything from Earth's perspective. A very stunning, immersive installation. They also had a section where they put stars from constellations like Orion with the depth separation that we cannot view from earth (since we see them head on) with a little viewfinder that enabled you to line up the lights and see which constellation they made. Pretty cool, alas, they didn't allow pictures.
They DID allow pictures on the Skyway though. There were stunning views of Tokyo. Of course, I had to take a panoramic shot: