One of the things that I documented was how to link your journal page directly to LiveJournal Chat... I even found a way to add a LiveJournal Chat link (or any kind of link, really...) to journals owned by unpaid users or those who haven't created a style for their journal site.
As far as LiveJournal Chat goes, I could use some feedback on how well it works (or doesn't work) for you, since I am trying to make sure that this implementation will work for another website I am creating. (I'd tell you all about it, but I'd rather wait until I have actually got the site up first. That way I'll feel less stressed if it doesn't get off the ground any time soon...)
If you have the time, take a look at LiveJournal Chat and let me know what you think.