IRC

Cyphen.net has an IRC server!

If you’re using Windows you can grab the auto-installing X-Chat client I put together:

X-Chat Client (Tested to work properly in XP, may not work in Vista)

If you prefer to use your own client (or don’t use Windows) you can use these settings:

Server: irc.cyphen.net

Port: 6697 (SSL)

Chanel: #cyphen.net

Note: I don’t have a valid SSL certificate, so if you need to then disable checking for valid certificates in your client of choice.
You can use the online IRC client here.