We have an IRC (click here if you don't know what IRC is) channel on freenode that gets some traffic. There's a fair amount of development talk there, but there's plenty more to be had.
Joining the IRC Channel
Pick your favorite IRC client and connect to freenode. You can connect to the server irc.freenode.net, then join #armagetron using the user interface of your IRC client or the command "/join #armagetron"
Once there, you'll find plenty to talk about, I'm sure. There is one thing you should not do, however: enter the channel, say "hi!", maybe ask a question, and leave after a minute of getting no response. If there is no discussion currently going on, everyone has their chat windows in the background and simply won't notice you in time. Have some patience.
There's a bot there that gives some additional features. For a list of stuff, type:
Then, for example for the Weather module, do:
This combination will register you as a user of the bot and give you access to more features, such as a welcome message (herald):
/msg armabot register <username> <password>
After registering you need to identify to armabot using
/msg armabot identify <username> <password>
You can leave a note for another user like this:
#message Lucifer_arma You're a prick
When the other user comes into the channel and says something armabot will automatically deliver the notes as private messages. To see which users have notes waiting to be delivered use
You can also get RSS feeds, math calculations and conversions, coin-flipping, and other neat things. It's intended that we'll provide a module to query servers and see who's playing where, but that's not yet implemented. You can get a list of servers and the number of users playing there with the command #armaservers (somehow unreliable, but usually it works) or get help on a console command in arma using #armaconfig.
So have fun with it!