I believe that most of the major carriers in america will provide you with an 800# and a pin that will allow you to bill a call from a pay-phone to your home account. I have one from MCI that I got a decade ago. I memorized it. I carry it with me at all times (in my head) and if I can make a call (have fingeres and a phone with a dial-tone) I can call on that number. I have occasionally run into a payphone that won't give a dial-tone without a coin but IIRC they didn't have a slot for a card either. Most pay-phones will allow collect calls and 800# calls so I've been good with this memorized 10 digit number + pin.