Internet Relay Chat is a worldwide text chat service with many thousands of users among various irc 'networks.'
The Freenode IRC network has a #haskell channel, as of November 2005, we average about one hundred eighty people, and we have some excellent discussions.
As of 2005-10-28 our high water mark is 206 unique clients (though that's at least three bots).
If you point your irc client to irc.freenode.net and then join the #haskell channel, you'll be there.
Currently we have about half newbies learning from the experienced half, but any Haskell related conversation is welcome.