Open-id is a way for you to leave comments and keep track of people on other journaling systems. When you create an Open ID account, say on InsaneJournal, all you have is an info page and a friends page. But not only will you be able to comment, you will also be able to see friends-only entries.
The site that you log in as is your ID server; if you are using your LJ name, you have to be logged into LJ when you are browsing and commenting on other sites that use Open ID.
The clearest explaination I have found is by Cmshaw at this post:
http://cmshaw.livejournal.com/453907.html . She was kind enough to allow me to copy her directions here, for my own knowledge and to tell my flist. These are all of her research and words; I just changed the examples and some of the formatting so it is easier for myself to read.
Cmshaw's how to...
...log into insanejournal with your livejournal account
1) Make sure you are currently logged into livejournal. If you're not permanently logged in (check "Remember me" to stay logged in), you'll need to use the same browser for the rest of these steps.
2) Go to
http://www.insanejournal.com/openid/, or else find a public post on an insanejournal account and click to leave a comment on it (it doesn't matter if you're replying to the entry or to another comment). You may need to select "More Options" to get the full OpenID options.
3) If you're posting a comment, in your From: options, select "OpenID" and select "Log in" beside it. In the Identity URL box, type "[username].livejournal.com" or, if your username begins with or ends with an underscore (this makes it unavailable as a subdomain), type "users.livejournal.com/[username]".
4) If you're posting a comment, enter it and click "post comment"; otherwise, click the login button.
5) The first time you do this, the browser will redirect to livejournal and you will be prompted to authenticate to insanejournal.com. You can select "once" or "always" (or "no", although that makes the rest of these steps silly!); if you select "always", this is the only time you'll have to do this.
6) Once you validate to livejournal that you want to use your OpenID account on insanejournal, you will be returned to insanejournal. If you were posting a comment, it will be posted.
7) Now you're logged in to insanejournal as "[username].livejournal.com" (or "users.livejournal.com/[username]"). (You'll see in various places that you'll show up as a username with a random collection of letters -- user ext-### on insanejournal.)
Things to do: upload icons (
http://www.insanejournal.com/editpics.bml); add friends and read your flist; write down your profile URL; post more comments without having to log in; enter an email address for comment notifications (see below).
...get comment notifications for OpenID comments
1) Log in with your OpenID (go to
http://www.insanejournal.com/openid or leave a comment).
2) Go to Edit Profile. Scroll down to find the section for your primary email address. (Different clones on different versions may display this in different ways. In Insanejournal this is
http://www.insanejournal.com/manage/profile/.) You'll need to enter an email address here.
3) Go to Email Management or Validate Email (again, different clones will call this something different; in Insanejournal it is
http://www.insanejournal.com/tools/emailmanage.bml). Send yourself a validation email.
4) Respond to the validation email once it arrives.
5) You will NOT automatically receive comment notifications. To be notified, you should click on the "track this" link (the standard icon is a pushpin) for a thread or, if the site doesn't allow thread tracking, on the entry as a whole. This will take you to the message center where you can choose what notifications to receive.
...allow people from livejournal to read and comment on your friends-locked insanejournal entries
1) Make sure that they have gone through the process above to set up an OpenID account on insanejournal.
2) Log into your insanejournal account.
3) Either find a comment made by your friend's OpenID account and click on the usericon (an orange I with a dark swirl around it) or have your friend send you their profile URL (which they should have remembered to write down in step 7 above).
4) Click on the little "Add friend" icon at the top. Now you can add them just like any other friend.
Note: Your friends must be logged into insanejournal with their OpenID accounts in order to read your locked entries; being logged into their livejournal accounts is not enough. The "Remember me" option to stay logged in is available to OpenID accounts.
ETA Note: You must allow anonymous posting in order to allow OpenID posting. If you have set your comment level to "Registered users only", friended OpenID users will be able to read your friends-locked posts but will not be able to comment on any posts of yours.