Alexander Graham Bell's first telephone conversation was supposedly brief: "Mr. Watson, come here. I want you!"
Not many people know this, but the reason he got off the line so quickly was that one of his kids was hovering nearby, hopping up and down and making urgent gestures, waiting to use the phone. The inseparability of teenagers and telephones has been a cliché of adolescence ever since.
Except for those of us who grew up with party lines. My family's farm was one of several that shared a phone line. Each household had its own unique combination of long and short rings, but all the phones rang whenever any family got a call. This meant anyone on the line could (and sometimes did) listen to anyone else's conversations.
Sometimes this was inadvertent—if you picked up the phone to make a call and someone else was using it, you couldn't help but overhear a few words. At other times it was deliberate listening in. This, for some reason I haven't been able to find, was called "rubbering."
On some party lines, certain people (okay, certain women) had the reputation, deserved or not, for always listening in. My mother and my grandmothers, having plenty of other things to do, weren't among them. There may have been a few people who did listen all the time, although I doubt that many of the conversations were all that interesting. After all, everyone knew it was a party line, which provided a strong incentive to be circumspect.
I used to hate it when my boyfriend would call. Not because I didn't want to talk to him, but because I worried that he might say too much. Living in town and not being used to a party line, he hadn't been trained to automatically censor his conversations with eavesdroppers in mind. Not, I hasten to point out, that we ever said (or did, for that matter) anything particularly shocking, illegal, or even interesting. Still, the idea that neighbors who had known me since I was born might be listening tended to keep the conversations both brief and discreet.
As phone technology developed, party lines were phased out. Ironically, though, as technology continues to change with cell phones and the Internet, we may be coming back to communal communication. A conference call, after all, is nothing but the equivalent of a party line—the only difference being that everyone knows who else is on the line.
And with cell phones, people are once again having phone conversations in the company of uninvited listeners. The difference is that the listeners aren't choosing to pick up the phone and "rubber in." Their involvement is involuntary, and if they don't want to hear the conversation they can't just hang up.
Thank goodness at least for texting. It not only protects the privacy of the callers, but it protects innocent bystanders from being a party to their conversations.
The Internet, too, is really nothing but an enormous, international party line. You can say anything you want to there. It's always wise, however, to remember that you never know who might be listening.
Practical Prairie Woman 
Ginny and I both worked in the telephone industry for a time. We both worked for telephone companies in California, and she was a telephone operator in Sioux City before we were married. She was always tickled when a call went to the tiny town of Salix, Iowa. They had one operator and she must have know every patron in their system. Some times a call would come in the operator would answer,”She isn’t home now. She went to Sioux City.” Now that is personal service. Today, you are asked to Press one for English, Press two for Spanish. Ginny says this modern phone system has set up electonic barriers. But without computers running the phone system, it would take millions of people connecting us manually. Sic transic Munde.