In the morning I went to the Louvre, looked around a while, had lunch at a nearby café, then went back and poked around a little more before closing time.
The popular stuff was really busy, so I spent more time looking at some of the neat old greek pottery, the medieval Louvre foundations in the basement, and a temporary exhibit of Islamic artifacts.
At night I went to the Parc de Villette to see "Kilo", a show put on by the graduates of the national circus school. It was a really neat show, though somewhat rough around the edges, and full of all sorts of crazy ideas going on all at once where it might sometimes have been better to simplify a bit.
It turned out they had rather good food for sale on-site, before and after. If I'd understood I would have shown up earlier! But I enjoyed some of the yummy carrot-and-orange soup afterwards. I walked back by way of the outdoor movie, which was "Total Recall". I succumbed to temptation and sat down to watch it, which was a mistake--it wasn't that great.