They can do some of the same things, but not all of them. For instance, I use Macjournal mainly for posting to this blog, Yojimbo does not have this functionality. MacJournal is really designed with journaling and blogging in mind first. Yojimbo is more of a "digital shoebox" application. At this point, I could probably get away with putting most of the items I have in Yojimbo into MacJournal and calling it done but I just have not got around to making such a choice yet.