When you get disconnected on the phone, who is supposed to call the other person back? Sometimes you end up calling each other at the same time and both get busy signals. Sometimes you just wait for the other person to call you back and it never happens. I've come up with a solution to this problem with my girlfriend. We developed a rule to determine who should initiate the phone call after the call drops.
The system goes like this: if you initiated the call in the first place, then you initiate the call after it gets dropped. Exception: if one person is driving, then the driver does not make the outgoing call.
Try this system. If everyone starts using it, then this could solve the coordination problem. Right now this solution only works for me and my girlfriend. I'm trying to transition some people that I regularly talk to on the phone to use this system. Who knows, this could become the new standard.