Early this Monday we got new trash cans, the big ones with two wheels that the trucks pick up with mechanical arms. My kids thought it was the most exciting thing since the invention of the cardboard box!
The transporters work on stuffed animals too! The bins are so big that the kids can hide in them, hide stuff in them and just have a grand ol' time playing! Too bad we'll have to use them for trash and recycling some day soon!
At least we don't seem to run out of cardboard boxes and empty peanut butter jars around here, since those are the containers of last resort for animal transport/housing/whatever.
Give a kid a cardboard box or two, and a roll of masking tape, and see what appears!