I've added an OpenID authentication system to my blog. Mostly this is so that hopefully friends of mine who read the blog that are on LJ will have an easier time being able to post comments since they should just be able to use their LJ ID to authenticate to do the comments.
Please let me know if this is working or not working as I'm pretty interested in seeing this sort of system becoming more common and adoption among the fringe can sometimes be a good proving ground for the core.
Update: I've switched over to the default template in order to allow the OpenID system show up in the comments. I had been thinking of doing a major theme change anyway now I just have to find one that supports what I want in it, or hack one together myself (which seems much less likely).