WordPress.com announced today that you can use your WordPress.com blog URL as an OpenID. That means you can log into sites supporting OpenID using that URL. You just enter the URL, click on the sign in button, and you’ll be directed to WordPress.com to sign in if you’re not already and to confirm that you want to pass your WordPress.com identity to the site. Note you must be an administrator on the WordPress.com blog you’re using, and the OpenIDs belong to a blog as a whole not just one user on the blog, so it probably won’t work so well for blogs with multiple users.
This is great if you use a custom domain name like http://www.yourname.com mapped to WordPress.com but not so great if you’re just using WordPress.com’s basic yourblogname.wordpress.com URL. As we move towards a world of single sign-on, you will want to be in control of your identity. Ideally, your OpenID username (which is expressed as a URL) will be under your control and will represent you independently of any particular platform or service. It should use a domain name you own–probably yourname.com if you are fortunate and/or foresightful enough to have it.
If you do own a URL you’d like to use as your OpenID, with WordPress.com or someone else as your OpenID provider, that’s pretty easy to do:
2. Delegate OpenID handling from your home page (e.g., index.html) on your OpenID domain to your service provider by adding this to the <head> section of the HTML (example given for WordPress.com):
<link rel=”openid.server” href=”http://yourblogname.wordpress.com/?openidserver=1″>
<link rel=”openid.delegate” href=”http://yourblogname.wordpress.com/”>
To find the OpenID server name to use in the first link, go to your OpenID page at your OpenID service provider, do a “view source” on the page, and search for “openid.server” within the text. You’ll see the server specified right there. The URL in the second link is just your URL at your OpenID provider. Now, should you ever want to switch OpenID providers, you just edit your home page. Your OpenID username stays the same.
Once you’ve done this, you should be able to login at any OpenID-enabled services, but not, unfortunately, WordPress.com blogs themselves. WordPress.com is only an OpenID provider right now; it doesn’t not support OpenID logins itself.