OpenID: Could They Make This More Confusing?

I’ve been hearing about OpenID, and it seems like a good idea in theory – so I thought I’d check it out. I head on over to the OpenID site, and I click on the “Get an OpenID” link. I’m taken to a page that says the following:

Surprise! You may already have one. If you use any of the following services, you already have your own OpenID:”

One of the sites they list is Smugmug (username.smugmug.com), where my username is jasondunn. So my OpenID should be jasondunn, right? Ok, so how do I manage it? I head over to myOpenID, and I click on the “Sign In To Your Account” link, because the main OpenID site told me that if I’m signed up with Smugmug I already have an OpenID. I try logging in with my Smugmug username and password, and that doesn’t work. So I decide to create a new OpenID account from scratch, which I complete successfully using the username jasondunn. So how could I take that username if it was taken first at Smugmug?

None of this makes any sense.