San Francisco's MOMA has a nice show up called Joseph Cornell: Navigating the Imagination.
He is best known as a reclusive artist who created "boxes" containing collages. These boxes are essentially display cases that provide frames/borders for the work. Although related to the surrealists and Dadaists and maybe other sub-isms of modernism, his work doesn't seem to have anything to do with instruction or programs.
This is not to say he did not have something of a theoretical basis for what he was doing: the work is very much intentional. There are wonderful series where an idea or motif is explored repeatedly, such as the wonderful palace boxes that evoke both the 18th century and fairy tales.
One of the boxes in the show has an image of an owl in a tree. Originally it was lit constantly by a small internal bulb. To save the material of the piece the conservators have set it up so that you push a button below the piece to light it. Dave had fun sitting nearby on a bench and hooting softly whenever someone pushed the button. (We were surprised how many viewers did not push the button.)
The show is up through 1/6/08, at SFMOMA: http://www.sfmoma.org/.
Here is a website from the museum where the show originated:http://pem.org/cornell/.