Can you suggest some working example of it? I tried Authlogic and Devise withous success.
I spent about a week trying (unsuccessfully) to get open_id_authentication working. I was trying to use Authlogic and all the associated gems and plugins. I could not get things working the way I wanted. (Authentication would only work with the :action(/:id) route enabled, but when that was enabled, my other controllers wouldn't work because something in the plugin was stripping the params hash - very frustrating).
However, I was finally able to get OpenID working using Devise (http://github.com/plataformatec/devise) and devise_openid_authenticatable (http://github.com/nbudin/devise_openid_authenticatable). I was able to follow the readme's on both of the pages to get everything working exactly like I wanted it to. Simple. Straight forward. And Rails 3.0 compatible.