Visiting sites or blogging and commenting out posts may be complicated, due to change of authentication. Enter OpenID (http://openid.net/), an organization whose goal is to let people “single sign-on” over multiple sites/blogs. Without the disadvantages of a centralized authenticator, OpenID offers a way to use a URL as one’s identity when propted for a login. The software to run an OpenID server is free, but there are free servers that can be used as well: videntity.org serves identities and vcards. One stores a profile, and uses a URL to log into participating sites. Among which, the nice blogger LiveJournal.