AAMOF and FWIW, a couple of days ago, I invented the 'exact opposite' of both the unplugger and the useless finger switcher for my robot (conceptual stage only). The robot has a regular on-off switch that shuts it down completely.
When the robot comes into the charging dock, and seats itself correctly, the on-off switch will be shut off by a servo rotator. The batteries will charge, but robot is otherwise dead to the world.
Once charging is complete, the charger will shut off. The charging dock, however, will be RF-linked to my home automation network (currently under construction). In general, the robot will likely be turned off completely. However, the automation network will be able to send a signal to the servo rotator, and flip the switch on the robot to on, as desired, to send the robot back into action.
This may sound like a
type of project, but it's not really. Eg, my roombavac does NOT have an on-off switch, and once it's out of its charger, and just sitting around doing nothing, the battery will go dead in a week or so. You have to remove the battery to prevent this. BIG PITN. I want my robot to not be so dumb as to eat its batteries when not in service. Voila.