1) Add "[User Info]" to the row of quicklinks along the top, next to "[Most Recent Entries]", "[Calendar View]", and "[Friends]". In my experience, new users often do not realize that clicking on "Joe Smith" in the sentence "Below are the N most recent entries recorded in Joe Smith's LiveJournal" will give them information about Joe Smith. Moving the userinfo link to the line above has minimal cost and makes the functionality more apparent.
2) In the friends view, align usernames and userpics with the top of the entry instead of the middle, as is done in the default community lastn view. In the current style, you can't tell who wrote a very long entry until you scroll down. I see no cost to doing this, and a small but noticable usability improvement.
Implementation should be trivial for both changes, if we decide to do them.