Use LJ Talk!

[skyfaller]

If you know what Jabber is, and use a multi-IM client like Gaim or Adium, you should check out LJ Talk (see also the post on lj_dev)... basically Livejournal is providing a Jabber server which automatically populates your Jabber buddy list with your LJ friends. They're working on their own client, and you will be able to talk to anybody else who is using Jabber, e.g. Gtalk, Project Gizmo, etc. I'm on LJ Talk right now, and I'm posting this through the LJ bot (Frank)... you can IM him saying "post:" and it will post it to your Livejournal for you. I don't know why you would ever use that, but hey, if you want to post from your IM client, now you can.