A new bug/attack on LJ has made it nearly impossible to keep the service up for more than a few minutes. I have been working on it non-stop since brad went to bed, however.
Now, if you are reading this as of 10:30am EST, you are probably a paid member. I managed to get the paid members server to handle http://livejournal.com/users requests -most- of the time. We're working as fast as we can to restore things to normal on all servers.
[Update:] It more or less works now. I have isolated the bug and prepared a temporary workaround until one of us here managed to fix the actual bug. Enjoy your day.
[Update 2:] Yeah, we know userpics aren't working right now. That will be fixed a little later.