Sam Ruby - OpenID for non-SuperUsers:

"Based on the results of my Unobtrusive OpenID post, it is quite evident that there is a lot of partial knowledge about OpenID out there. While my knowledge on the subject is far from complete, this post is my attempt to share what I have learned with others. The target audience for the bulk of this post is people who are capable of adding autodiscovery links to their blog templates, may be able to install a small PHP script and/or knows what a HTTP header is."