I'm not sure but i Just tried it 2/3/10 and it didn't work
from yubico's website
Yubico OpenID Server
There are two ways to use the Yubico OpenID server. The simplest is
to go to any site which supports
OpenID and log in to it using the
following OpenID URL:
You will then be redirected to our OpenID server, and can login to the
site authenticated using your YubiKey.
If you wish to use a more personal OpenID URL, you need to set up your
own web site and be able to modify the
HTML code for it. Insert the following
markup into the of the HTML
document at your own home page:
<link rel="openid.server" href="http://openid.yubico.com/server.php" />
<link rel="openid.delegate" href="http://openid.yubico.com/server.php/idpage?user=cccccccbihth"
Once you have made this change, you should be able to use your own URL
as the OpenID URL when using any
OpenID enabled site.
You can verify that it is working by using the external OpenID Checkup
You can read more about OpenID.