Finally starting to get a handle on this OpenID stuff, although I have to admit it's taken some rattling around in my head to actually get it to come together. The "Aha!" moment just came something like ten minutes ago, with this tutorial. Took me about five minutes and kapow, I could log into wikitravel, using libgrunt.blogspot.com as my ID and the fine folks at myopenid as a server.
It helped me to think of it as sorta like LDAP, which I've been using with great success on my class's Drupal-based podcast server.
In my opinion, every university with a centralized ID scheme -- like we have here locally -- should implement a OpenID server. We already have LDAP; OpenID seems like a natural progression. Then imagine not having to create accounts on each and every Super Spiffy New social network -- I've already got a text file full of what must be fifty to a hundred different logins to as many different services. Good thing I encrypt it, because.. well, I'd rather not think about it.
Anyway, if you've been hearing about OpenID and want to see it in action, try that tutorial.