My middle school had a pay phone in the lobby. After-school activities had a variable end time so when I needed my mom to pick me up I’d call her collect. She never accepted the charges, but knew it was time to head over to the school.
- "You have a collect call from AtTheStationMyBusLeavesIn18Minutes. Do you wish to accept the charges?"
- "No"
For the unfamiliar, the collect call recording asked for your name and played it back to the call recipient. You had a a small window whereby you could get info across.
“You have a collect call from ‘555 4784’, would you like to accept the charges?”
Then whoever could just call you back.
The real power was unlocked with a Blue Box - a phone phreaking device that played the same tones as if money was entered into the pay phone. You could trick the phone and make your call. I remember looping the tone on a cassette tape and calling some random number in Japan for several dollars worth of tones. Good times.