Bulletin Board Systems.
In Boston we had this cool BBS where you went into an interactive text adventure and people helped you along in the game.
People you got to know by thier handles. It was a lot of fun.
We also had an online trivia game that allowed free text entry. After the answer was revealed, we all chatted about it in real time. It was fun too.
I also ran a Macintosh BBS called MacBoston and was amazed that people from all over the US dialed in.....
The next thing that was really cool on a national level was Byte Magazine's online service called bix.
I'll always remember fondly Jerry Pournelle's conversations....