Nail Electronics (once and for all)
Many people who "do" electronics as a pastime or as a career feel the urge to convey their knowledge and experience to the younger generation. To do that, all sorts of systems have been proposed, but only few are as simple as the one presented here. Draw a schematic on a sheet of paper, stick it on a piece of wood, at the wire junctions hammer in some nails, then solder the parts to the nails. Great fun and not unlike the way radio and TV electronics got assembled in the fifties and sixties.