Can a sheet of plywood glide across the floor on a cushion of air? A hovercraft works by pumping air under a flat surface. The trapped air lifts the craft off the ground and almost eliminates friction. You cut a round disk from plywood and staple a plastic sheet to the bottom. A small disk pinned at the center holds the plastic in place and creates a donut-shaped air pocket. You cut six vent holes in the plastic near the center. Then you attach a leaf blower to a hole drilled in the plywood. Turn on the blower and the plastic inflates. The hovercraft lifts slightly and glides across smooth floors with very little resistance.