For those who don't read lj_dev, LJ has a new feature in beta - integrated Jabber. For those who don't know, Jabber is an open IM protocol. It is used by a few networks, most notably Google Talk. The details are in this post. You need an IM client that supports Jabber (there is a list there - personally I use Gaim for IM). Then you just add a new account using your LJ user name and password, with 'livejournal.com' as the server. Anyone on your friends list is automatically on your IM 'buddy list' to start.