The OpenID spec is an interesting thing.
Since you're already logged into say, LiveJournal, you trust and are active on the site. That means that your Livejournal authentication expires rarely. On the other hand, you post here rarely. Authentication would be a big pain in the ass to remember a separate password just to post to this blog three times a year in comments.
Enter OpenID. This will let you use your exisiting (Livejournal) authentication to also authenticate yourself here, or any OpenID enabled* site. It will transfer you to Livejournal for a moment, ask you if you want this site to know who you are on Livejournal and then tell that to this site. But none of your authentication needs to even be transmitted to this site.
Damned convienent, you might say. I agree. Some buddies may have noticed infornography.gotdns.com popping up in their LJ user list. That's me, using it in the reverse. I already have a blog, so why be anonymous or create a livejournal account just for commenting? You could even trust that user if you do a friends only page, as it's still an authenticated user.
What's possible for OpenID's future? Imagine your friends list populated not just with Livejournal friends, but my blog posts just the same. Never having to create accounts on Slashdot, kuro5hin or other forums. Tying together FOAF (Friend of a friend) data, not only with blogs, but with people you regularly communicate (via blog comments, forums, etc).
So, with that in mind, I announce that I've done a bit more work on a WordPress plugin for OpenID. Try it out. Use it, break it, talk to me about it. There's no server (yet), but OpenID servers are easy to come by;
are two existing examples. (And linking them to your current blog is easy, if you're not a Livejournal member)