I use openID on some sites for logging in (most notably the http://stackoverflow.com sites). I set up a myopenid account a long time ago. But I didn't want to have http://reinout.myopenid.com/ as my ID as that's a URL that's not under my control. What if myopenid gets cancelled? It is a free service.
Luckily the openID protocol allows you to "redirect". An ID is a URL. And if you put a couple of link tags in your preferred URL's html <head> element you can use that URL as your openID.
So I used http://reinout.vanrees.org/ as my openID url. I had the following in my header:
<link rel="openid.server"
href="http://www.myopenid.com/server" />
<link rel="openid.delegate"
href="http://reinout.myopenid.com" />
<link rel="openid2.local_id"
href="http://reinout.myopenid.com" />
<link rel="openid2.provider"
href="http://www.myopenid.com/server" />
<meta http-equiv="X-XRDS-Location"
content="http://www.myopenid.com/xrds?username=reinout.myopenid.com"
/>
Not totally sure if everything was needed, though. A bit of a mix between openID 1 and 2.
Yesterday I got an email that myopenid is stopping in a few months. Ah, so I have to move. The one that seemed handiest to me was to use my google account. The magic incantation could be found on stackoverflow. So I changed the stuff in my homepage's <head> to this:
<link rel="openid2.provider"
href="https://www.google.com/accounts/o8/ud?source=profiles" />
<link rel="openid2.local_id"
href="https://profiles.google.com/reinoutvanrees" />
Tadaah! I can still log in with my same http://reinout.vanrees.org/ openID url. Hurray for building ID delegation into the protocol!
(And a solid pat on the back for myself for setting it up with delegation in the first place, of course) :-)