Physical /dev/null

Re-program the system you are on to stream data which normally simply disappears into the proverbial bit-bucket to an RS-232 port or similar, to which a device would be connected that would in some physical way represent the discarded data (possibly, a bank of LEDs, or, for the wealthy, a dedicated SVGA monitor displaying a comical rendering of a trashcan which is filling with data, represented by chaotically printed, out-of-alignment green characters.) Alternatively, a public radio channel could be set up. Each machine that has a dev/null could be set by its master (voluntarily) to broadcast the tossed-out data with a short range transmitter. This way, other people could ride around with laptops connected to simple digital receivers, as perhaps "one man's trash is another's treasure."