OpenID is a free and easy way to use a single identity across the Internet. With OpenID, you can log into many websites with the same identity. This sames a lot of time in filling out registration forms.
You get to choose the OpenID Provider that best meets your needs and most importantly that you trust. At the same time, your OpenID can stay with you, no matter which Provider you move to.
OpenID is still in the adoption phase and is becoming more and more popular, as large organizations like AOL, Microsoft, Sun, Novell, etc. begin to accept and provide OpenIDs. Today it is estimated that there are over 160-million OpenID enabled URIs with nearly ten-thousand sites supporting OpenID logins.
You already have an OpenID if you use any of the following services:
AOL – openid.aol.com/screenname
Blogger – blogname.blogspot.com
Flickr - flickr.com/photos/username
LiveDoor – profile.livedoor.com/username
LiveJournal – username.livejournal.com
SmugMug – username.smugmug.com
Technorati – technorati.com/people/technorati/username
Vox – member.vox.com
Yahoo - openid.yahoo.com
WordPress.com – username.wordpress.com
You can also sign up for an OpenID with any of these providers:
ClaimID – claimID is the free, easy way to manage your online identity with OpenID.
myOpenID – Secure, free, hosted OpenID server by JanRain.
VeriSign’s Personal Identity Provider – Free OpenID Provider with support for multi-factor authentication.
myID.net – Free OpenID Provider with support for groups and Korean language.
myVidoop – Free OpenID Provider that eliminates passwords with security features, customization, and
