zlacker

I vaguely remember (sometime in the 80s) sticking a straightened paperclip into a small hole on the face of a payphone to avoid having to drop a dime / quarters, and being able to call anywhere.

>>chrisw+(OP)
If I recall, you’d stick the straightened paperclip into one of the holes on the mouthpiece and touch the other end of the paperclip to some metal part on main phone body.

War Games used a pull tab from an aluminum can to a similar effect?

(It’s been a while.)