Removing this FAQ as it was written at a time when mobile apps either didn't exist or were much more primative.
http://www.livejournal.com/support/faq/187.html sufficiently covers issues related to email posting, which is the method this is promoting. Preserving raw FAQ code below lj-cut.
This FAQ applies only to
Paid,
Plus, and Permanent accounts. To check your account type, please see your
profile page.
→
More information on account levels →
Paid Account benefitsPaid, Permanent, and Plus Account users can post pictures to ScrapBook from cell phones. First, you need to set up
your ScrapBook account as well as
your mobile posting settings.
Body:
Before sending a message, you need to use the
Mobile Post Settings page to add the email address of your cell phone to your Allowed Sender Addresses list and to specify the default settings for pictures uploaded by email.
Creating a Message
This procedure varies with different cell phones. On many phones you can view the desired image and then choose to send it from the options or properties menu, or to compose a multimedia message (sometimes called MMS). After you've found a working method, send your message to the
post.livejournal.com mobile posting email address. You may find it easier to save your address with PIN in your phone's address book, so you don't have to retype it.
Optional Features
Once LiveJournal receives your picture email, the picture is stored in your ScrapBook, and a post is created with the default layout.