I've been following the migration of LiveJournal and GreatestJournal uses to other sites for a day or two. A lot of users are dis-satisfied about having to move hundred of entries and icons by hand. I poked around a bit and found that
LJ-Sec works wonderfully. It pretty much moves everything except for comments. A note with custom filters though is they should be pre-created before exporting and importing them to another LJ-Clone site. That's pretty much the only fault. When you're re-creating for the journal you're going to import the entries to make that you have the people you to have access there and not someone you don't want to read them.
There's also a mulit-icon uploader floating around but I have caught sight of it yet. We all know that uploading icons one by one is a time consuming task. Hopefully I'll come across it soon I've got a ton of icons I would love to update at Insanejournal.