Stephanie Leary

This plugin appends the author’s display name to posts and/or pages. There is an option to turn off the display on your own site, so the signature is visible only in feeds and crossposted content.

Post Signature

Appends the post author's display name to posts. Useful for multi-author blogs that are crossposted elsewhere, such as LiveJournal or Facebook.

GrayHunter

LJ-XP-SW is a WordPress 2.5+ plugin, that has the ability to crosspost a blog text to your LiveJournal (or LiveJournal-based clone) account. It can crosspost to communities, and even has a customizeable header and footer, and allows you to direct would-be LJ comments to your WP blog instead!
But the main feature is that the plugin does not crosspost the exact text of your article. There is a special field where you can write your Alternate Annonce. So, this plugin helps your blog avoid fines for plagiarism. This is the realy Safe Way LiveJournal Crossposter.
Features:
<ul>
<li>The plugin does not crosspost the exact text of your article.</li>
<li>There is a special field where you can write your Alternate Annonce. So, this plugin helps your blog avoid fines for plagiarism. This is the realy Safe Way LiveJournal Crossposter.</li>
</ul>

LJ-XP-SW

LJ-XP-SW a plugin, that has the ability to crosspost a blog text to your LiveJournal (or LiveJournal-based clone) account in safe way.

Post Signature vs LJ-XP-SW