A relatively recent but little known feature went live as far back as June.
On the main Log In page you'll see two additional log in options: an "Expiration:" option, which lets you choose whether you want to be automatically logged out of your account when you close your web browser, and a "Bind to IP address:" option for increased security. Because these options couldn't be specified using the "mini" log in form at the top of every LiveJournal page, there was no way to set them without going to the main Log In page.
Now, when you log in using either form, you can append an exclamation mark to your user name to tell LiveJournal's server to disable the automatic log out feature, and you can also add a "less than" symbol to bind your session cookie to your computer's IP address. Examples:
jayo!- "permanent" log in
jayo<- bind to IP address
jayo<!- set both options