Internet Relay Chat (IRC) is a group chat room. Useful for when you need more real-time communication than the mailing list can provide. It can be thought of as Twitter for old timers.
You can join us at #BLU on irc.freenode.net. Several BLU members regularly monitor the room.
If you just want to hop on with a quick question, you can use the IRC web client.
For more capability use an IRC client or an IM client that supports the IRC protocol. One such multi-platform client is Pidgin.