Finally! I got my news reader, Shrook, to let me read everyone's friend-locked posts. Here is the format for anyone wondering:

http://<ljusername>:<password>@<friendlj>.livejournal.com/data/rss?auth=digest

Just replace the <italics> words with first your user name at LiveJournal, then your password, and lastly the user name of your friend's blog.