In Australia back in the day, you could dial 199 on a pay phone which was the ring back number. Hang up, let it ring twice and then answer it. If you did it rig

In Australia back in the day, you could dial 199 on a pay phone which was the ring back number. Hang up, let it ring twice and then answer it. If you did it right there would be a warbling tone in the earpiece and you could then make any call for free.