ATTENTION: If you have an account with one of these sites, you can sign up at my site (and in fact any Drupal site) without a username or password:
That's from the official list, so check that for the most recent info. There's also another very important one that ain't there:
If you have an account at one of these places, you've got an OpenID.
What does that mean for me?
If you register for an account here, you don't have to come up with/repeat your username and password. Just plug in the URL, and you're good.
What do I get from registering here?
Uh, you... get to comment with your pretty pretty name attached? To be honest, I hadn't thought that far in advance. Maybe I'll lift some commenting requirements like the CAPTCHA or forced previews.
Maybe I'll mail you a cracker or something.
What if I have accounts at multiple places?
That's okay, they can all be linked in the settings panel.
What inspired this? Stack Overflow. Stack Overflow has this beautiful login/registration system: if you plug in your OpenID, that's it, you're a registered user. It'll remember you, but if you logout, you can log back in again with any of your OpenID URLs.
After having to jump through hoops to get registered anywhere, I eventually stopped registering at sites because I was so sick of making new credentials. At sign up, I had the lovely options of:
After that crap, Stack Overflow's system, due in part to OpenID, was a breath of fresh air.
NEVER MAKE ANOTHER CRAPPY USERNAME/PASSWORD PAIR. OPENID FO' LIFE!