Today I went to see the Joseph Cornell show at SFMOMA. His work is really incredible; he made both collages and boxes. I had seen a book about him, since my friend is a fan. But seeing it in person was much more moving and interesting. There is so much detail in his work. I really recommend this show, if you have a chance to see it. If not, this is a site that shows a lot of his work.
I came home wanting to make boxes of my own. I think I'll try to, at some point.
Picture of The Medici Prince from here.