My old Cross Posting application seemed to stop working when I upgraded to the latest version of Word Press, so I am trying a new one:

Live+Press allows WordPress posts to be automatically crossposted to a LiveJournal user blogs. This fork of the plugin is licensed under GPLv3. All contributions and suggestions are welcome. More plugin details and help can be found at the plugin home page on google code. Originally written by Jason Goldsmith By Tania Morell (aka digsite).

The old one was

LiveJournal Comments

1.0.3

This plugin displayes a number of comments in posts crossposted to LiveJournal. You can see how if works here. By Alexander Bishop.