This adds several features:
Caveat: Livejournal obviously won't let you repost or edit some other person's entry as anybody other than yourself, so LJ-Sec treats these entries differently. Read the documentation for more information.
You can override the default behavior in regards to the cache that stores journal entries, and utilize your own file. Again, this makes managing multiple journals easier.
You can now disable the "resynchronize on login" feature if you want.
New options for selecting posts: "Select inverse" and "Select My Entries Only" (the later option is mainly for community management)
Resynchronization should now show a bit less of those "server retries" errors.
LJ-Sec now requires the .NET framework version 2.0. IE 5.0 is also required. All posts also must be in Unicode in order for LJ-Sec to sync right (you can convert older posts here).
Backing up your journal using a tool like LJArchive is strongly recommended before using LJ-Sec.
Find the download for LJ-Sec at http://www.mp3vcr.com/ljsec/.