Just to clear things up about why I mention this when there are a few other similar things out there. This one truly is decentralised. Somewhere on the page you use as an ID is the address to your OpenID server. This site has a diagram explaining it all.
Well I have OpenID working at a basic level in Galaxia for signing up and logging in.
For signups though a user still needs to provide a username eventually to replace the url which will generally be too long.
I just noticed something on LiveJournal I hadn’t noticed before… OpenID. It’s a clever idea - a truly distributed identity management system. The idea is to allow you to login to websites using just a URL (in my case http://www.oliverbrown.me.uk/) and have everything done automatically.
In detail:
You login into a website that supports OpenID (like LiveJournal). The browser then checks that URL you gave for a bit of HTML that specifies your home server. The website then redirects your browser to that server and logs you in (and because of the joy of cookies etc. this should be automatic). The server then asks if you really want to share your identity with the site you specified and if so redirects back to the original site which now knows you are who you say you are (i.e. the owner of the url and actually registered with the server you specified).
It’s confusing but clever :)