It's a decentralized system to verify one's online identity. While it is not intended to prevent spam or create a trust metric, it solves the single sign-on problem without relying on any centralized website to confirm digital identity. OpenID users identify themselves with a URI or XRI which they own, such as for a blog or a home page. Since OpenID is decentralized, any website can employ OpenID software as a way for users to sign in.If you want to get your OpenID account, you might try to get it from one of OpenID providers. I already have my own OpenID which i have just registered at GetOpenID. Why do i pick this server? Because it is the one of the few OpenID servers that supports SSL. Some countries in Asia has already their own server for OpenID, for example Philippines, China, Japan, India, Korea. Too bad, Indonesia is not listed there because we don't have that currently.
How does it work? It's not that complicated. OpenID is based on unique URL which is now a common thing nowadays as Internet is now public and the technology has been considered mature. You can use your web page, your blog, your friendster page, your MySpace page, etc as your account as long it can be considered your identity. So, instead of using usernames and password, you will now use URL as your identifier when you tried to login to site that supports OpenID (for example OpenID Wiki).
Here's one simple example : I tried to login to OpenID Wiki using my OpenID which i got from GetOpenID and when i do that, the page redirect me to my Provider page (GetOpenID) and asked for my password as proof that i have the valid account there. When i have entered my password, they confirmed that i have the valid account and redirect me back to OpenID Wiki. Next, they asked me to pick a username for that (since i can use different username than the one i specified in my OpenID account) and that's it. I'm now registered to OpenID Wiki. Of course not all site supports for OpenID currently, so let's just wait until most site supports OpenID technology, but while waiting for that time, why don't you prepare yourself and get yourself and OpenID account?