I use them as controllers/monitors for remotely managing a 3d printer farm. At about $40 total extra per printer for the pi and associated hardware, and an open

I use them as controllers/monitors for remotely managing a 3d printer farm. At about $40 total extra per printer for the pi and associated hardware, and an open source utility called "octoprint", i'm able to remotely upload, monitor, cancel/pause, and have a camera feed to each printer. They also give some additional nice-to-haves by allowing me to upgrade the printer firmware remotely, and get very accurate print completion estimation times.