Unsurprisingly, OpenID is generating some confusion. But (so far) not in the ways I'd anticipated.
First off, AFAICT, Blurty, GreatestJournal, and JournalFen don't appear to support OpenID. (At least, I don't see that as one of the options on the 'post comment' page. Just anonymous, or user-of-that-site.)
CrazyLife, CommieJournal, DeadJournal, and Scribbld (and LiveJournal) offer a choice of anonymous, OpenID, or "Logged in user" (of that site) -- which to pick is probably reasonably unconfusing; I'll clear up the other potentially confusing bit below. (DeaadJournal has both "Logged in user" and "DeadJournal user" as options ... but unless you have a DJ account, you probably don't need to figure out what the difference is between those two choices.)
InsaneJournal, alas, has the potential for extra confusion: the radio button that ought to say either "InsaneJournal user" or "Logged in user", unfortunately says, "LiveJournal user", which can mislead the unwary LJ user into thinking it's an already-aimed-at-LJ configuration of OpenID or something, leading to frustration (and/or worry, when it looks as though IJ is asking for your LJ password, when IJ thinks you're trying to log in as an IJ user). I stuck a message about that in what I hope was an appropriate place, so maybe the wording will get fixed. In any case, if you're an LJ user following me over to IJ to leave a comment, you want the OpenID button.
Anyhow, here's how logging in with OpenID is supposed to work:
- I'm going to assume you're already logged in on LiveJournal...
- Select the "OpenID" radio button. Input fields labelled "Identity URL" and "Login?" will appear.
- Enter yourljusername.livejournal.com in the "Identity URL" box. Check the "Login?" box if staying logged in on this site as your LJ/OpenID identity might be convenient (like, if you expect to post more than one comment there, or want to go to the "edit profile" page afterward to associate a user-icon with your OpenID presence).
- Type in your comment, then click the "Post Comment" button.
- The page in that tab will be replaced by one with a LiveJournal URL (it'll start, "http://www.livejournal.com/openid/approve.bml?[...]") that's labelled "Grant identity validation?" It will say that, "Another site on the web wants to validate your LiveJournal identity. No information will be shared with them that isn't already public in your profile, only that you're who you've already told them you are (if you told them)." You'll have three buttons: "Yes; just this time", "Yes; always", and "No."
- Click one of the 'yes' buttons, and your comment will be posted.
What if you weren't already logged in at LiveJournal when you tried to use it for your OpenID credential? Instead of the "Grant identity validation?" page, you'll get one that says, "You need to be logged in to grant another site permission to know your identity."
And, of course, despite this description being written for a LiveJournal user commenting as a guest on another site via OpenID, it all works pretty much the same way if you're coming from a site other than LJ (a DJ user commenting at IJ, or a Blogger user commenting at LJ, or a Movable Type user commenting at Blogger; you just need to know the URL to use as your identity URL on the site where you have an account, to be able to log in via OpenID on other OpenID-enabled sites.
That's how it's supposed to work. That's how it worked for me while I was typing this up. One person so far has complained that it didn't, and I haven't yet sorted out why not -- drop me a line at dglenn@panix.com or via the LJ inbox if you can't get it to work, so I'll have some idea how often it breaks ... and if I'm lucky, wind up with enough info to send a bug report to whichever site seems to be the one causing the problem.