(if you already know OpenID then jump directly to the last section about
OpenID in PostNuke)
OpenID is a relatively new web-technology for managing your online identity. It's primary purpose is to facilitate Single Sign On across independent websites. This means you can create yourself an OpenID identity and use that for login in to different websites without having to retype your password over and over again.
Your OpenID consists of a URL, e.g., http://jornwildt.myopenid.com, and the OpenID technology makes it possible for you to prove that you own this URL. So, when you want to log in to a website supporting OpenID, you type this URL and then the website takes care of the rest (almost). EnThinnai Blog compares OpenIDs to credit cards: credit cards are issued by someone, it proves your identity at the issuer, you can have as many cards as you want, and in OpenID's case you can even use them to get access to places.
You can also use your OpenID to sign a weblog comment without the need to register as a user on that website. No one else can do that with your URL so your comments cannot be spoofed by anyone.
Take a look at these demos of how it works in some applications:
On Simon Willison's website you can also see some good examples of what OpenID can be used for.
One very interesting thing is that OpenID has just been adopted by Yahoo! So now each and every one of the 250 million Yahoo! users have their own OpenID identity. Even Google, IBM, Microsoft, and VeriSign have signed up to support the new technology. With that kind of backing OpenID is no more a kids toy.
OpenID is of course not the perfect solution for everything
(see for instance idcorner.org) but I would say it is close to perfect for Single Sign On and signing comments in the web/PostNuke world I live in.
If you want to start using your own OpenID then get one at
myopenid.com - it's free and it's all you need.
PostNuke should of course also have such a thing as OpenID for Single Sign On, user registration, signing comments and so on. So a new OpenID module for Single Sign On and user registration is on it's way (expected release in March or April). Have fun with it.
An OpenID implementation with PostNuke should also enable you to use your PostNuke installation as an Identity Provider, meaning that your OpenID could be YourName.YourSite.com. Hopefully the OpenID module will support this.
Other uses for OpenID in PostNuke could be to sign comments using the ezComments module or pre-allow access to certain Mediashare photo albums through your friends OpenIDs. Only the sky is the limit and OpenID is free for you to use and invent with.
Regards, Jørn Wildt