Maybe it should be mentioned that the Basic account on Livejournal now has advertising - you can't see it when you're logged in, but anyone who isn't logged in will see it when they look at your entries.
Don't get me wrong, I like livejournal a lot - bought a Permanent account three or four years ago and don't regret it. But it's something to consider in reaching a decision.
One alternative you might want to consider is Insanejournal, which doesn't have adverts on the blog pages with its free accounts - but they are on the page that you use to type entries etc. The management are allegedly more friendly to fanfic than livejournal, but it has a much smaller user base than LiveJournal and the user interface is a lot more primitive.
