A friend has long run a non-profit, called Futel, that’s sort of a hybrid community service and art project providing free payphones. As they describe it:
At Futel, we believe in the preservation of public telephone hardware as a means of providing access to the agora for everybody, and toward that goal we are privileged to provide free telephone calls, voicemail, and telephone-mediated services.
All services, including telephony and human interaction, are free from any Futel telephone.