How to log in all website without reguster

You want to log in to multiple sites quickly without the need
of multiple usernames and passwords? There is a simple way that I just figure out:USE OPEN ID：

http://openid.net/

maybe you will surprise that your blog’s address could be your open id , you have the open id already now,Use  your own blog,such as yourblog.logspot.com or yourblog. wordpress.com.

You can also use other account as your OPEN ID,such as google.com or flickr,see more on http://openid.net/.Or you make a new ID.