LiveJournal was down from approximately 2:15-2:50am PST (GMT-0800) thanks to a server crash. The site was sluggish, and the support board and certain other functions were down, until about 4:00am because of assorted fallout from the crash.
Sorry about that. Things should be back to normal now.
We don't know what caused the initial crash, but we've identified the cause of the subsequent fallout, and should be able to prevent such secondary damage from happening again.