OpenID is sort of the distributed Open Source version of that. There are two kinds of pieces: servers and consumers. The server is where you manage your username, password, and something similar to web cookies (the records that you’re logged in to that site over there, and that other site, and so on.) The consumers are websites you go to that ask for your username and password (or, in this case, your OpenID URL.)

OpenID servers are starting to become more and more common. If you have a LiveJournal username, you have an OpenID URL that points to LJ servers. If you’re a Yahoo user, there’s a way to use that as your single-sign-on with a Yahoo-based URL. There are plenty of packages that let you set up your own server (which is what I did on netninja.com). You can have OpenID accounts on all of these servers, but in the spirit of single-sign-on, you’d typically want to stick with only one.

Websites with OpenID client functionality are a little more rare, but are starting to appear. When you go to log in to one of these websites, you simply type your URL (in my case, netninja.com) and you’re temporarily redirected to the server to say yes/no (and possibly set up other details) and then redirected back to the original site. If you’ve used any Flickr toys or certain Facebook apps, you’ve probably seen a similar thing where you’re temporarily sent to Flickr to authorize. LiveJournal, obviously, supports signing up as an OpenID user. There are a few WordPress blogs around now that use OpenID for posting comments (e.g. TinyScreenfuls and hopefully mine, soon). This is nice because it’s not as spoofable as an anonymous comment and not as invasive as having to sign up for yet another account somewhere.

So, yeah–if you want to use LiveJournal as your OpenID provider/server, there’s nothing you need to do. When you run across a site that lets you log in with OpenID, just give them your LJ URL. If you want to use LiveJoural, but authorizing through some other OpenID server (as I’ve done), then yes–you effectively have to start from scratch. LiveJournal doesn’t provide a way of associating a 3rd-party OpenID account with an existing LJ user. Or, at least, not yet. (And with how they’ve been operating, I don’t expect such functionality any time soon.)

I just signed up for openid as well - but didn’t know why. Mostly to stake out my claim as “dmax” like I have everywhere else on the intertubes.

So, what good is it? What do I do now? (Go and read about it like everyone else does, dmax, you moron.)

Honestly, I am totally not getting it. I’m finding that, despite my claiming an openID of dmax and a claimID account of dmax - I can’t get into LJ without using those specific names, therefore meaning I have to start the LJ account all over again?

I’m missing something, if you could point me to something explicative.

Insert sales/marketing bro-guy “open the kimono” comment here.