There may be an easier way, but if you do one of those PDF exports and then use Calibre to transfer it to a mobi format, that might work. I don't know how well the formatting will hold up, though.
You can add your friends RSS feeds to Calibre individually, and Calibre can make you an ebook in the format of your choosing, without first having to create a PDF. The down side is that you will only see your friends public posts.
January 6 2013, 18:03:43 UTC 4 months ago
January 6 2013, 18:11:17 UTC 4 months ago
January 6 2013, 19:49:49 UTC 4 months ago
http://www.livejournal.com/support/f
You will have to be authenticated to access protected entries.
It creates a PDF of all the entries in the RSS feed, and it's very basic (no comments are included). then you can migrate the PDF to your e-reader.
January 6 2013, 20:45:51 UTC 4 months ago
Thanks for the suggestion.
April 11 2013, 11:22:33 UTC 1 month ago