It's no secret that kids love boxes.  They are the perfect vehicle for open-ended imaginative play!  I have a couple of box sharks on my hands.  We have a strict 'one box per child' rule in effect most of the time, otherwise we'd be taken over by cardboard boxes.  When a new one arrives from the mail or the store, the kids can choose to trade theirs and they often do.  When we grocery shopped on our way home from the airport I got two matching boxes.  Little did I know what fun they would be!  The girls have been playing with them for a week and a half solidly now!
I thought I had taken more pictures of this, but I guess not!  So far they have been stacked on top of one another and made into doll bunk beds, taken apart and used as cars, set on the couch and used as doll car seats, and then today they were turned upside down and made into horses.  Everyone got in on the fun!

Yes, that's another box you see in the background!  Our neighbors got a new dryer and I couldn't keep myself from asking for it.  Today it was a barn for the horses.  Now...what will they turn it all into tomorrow?