I think the LiveJournal chat feature might would be more popular if more people knew what a "Jabber" IM client actually was. Easiest one I've found to use is called "PSI" IM. Very easy to set up. Just put "email@example.com" in the Jabber ID field, and your LiveJournal password in the Password field. All the people on your "Friends" list will automatically be listed in the contacts window.