I've previously used LiveJournal for both personal use and for past classes, however I'm totally new when it comes to using Blogger. I've noticed a number of similarities between the two and a few minor differences.

• Both LiveJournal and Blogger allow you to create a user profile and upload a user picture or icon
• Both sites let you insert images or video into your post
• Both sites allow you to link to other blogs. On LJ these are considered "Friends", on Blogger you can "Follow" other blogs. I like the friends set-up on LJ better, seems more organized and more easily accessible.
• The actual journal and blog layouts are quite similar, and on both sites you can customize your layout
• Both LJ and Blogger let the poster diable or disallow comments
• LJ allows you to make your posts "Friends Only", "Private" or "Public" and create custom friend groups. I haven't seen anything similar on Blogger. Definitely an advantage of using LJ
• LJ lets you join various LiveJournal communities- another huge plus for LJ
  

Overall, I found these two services to be very similar. I think LJ has a few bonus features that aren't available on Blogger. Generally I prefer using LJ over Blogger, however in a professional or library setting I would use Blogger. I find the appearance of Blogger to be more professional than LJ (I think b/c I've also used LJ for personal use in the past, I have a hard time imagining using it in a library).