Even if you don't have children, you need something to entertain little ones that come visit. This board slides away under the sofa and is attached to small casters that help keep it up off the floor. It's a simple idea that could easily be done with board games or dry erase boards.
You can check out more on this space over at A Subtle Revely. What would you like to put on wheels to tuck out of the way for on-demand play time?