My cat, Ebony, loves getting in things. Boxes, baskets, drawers - whatever it is, she wants inside. We had a box lid laying on the floor of our apartment for a while, and she loved to go over and crouch inside it. I should have taken a picture!
The other day I was putting away my clothes in the dresser. I had my... er, fine lingerie drawer open, and she (of course) crawls in. I left the drawer open, but she didn't come out and I needed the drawer below the open one. So, I closed the top drawer and opened the one underneath and to my surprise, there she was! I guess she had gone back and crawled down.
One book I really love is called Cats Sleep Anywhere. It's a child's picture book with beautiful illustrations of all the random places cats will curl up. I love it because I can see my cats sleeping in random places too!
So, if you're looking for a nice kids' book for someone, I highly recommend that one. :-)