OpenID
There you go mate
now do I think its a good or bad idea? Mmmmm, not sure yet, more important is that whether you will have a choice.....
i.e. if ebay/paypal/hotmail/e-gold/amazon/ etc all decide its going to be their 'authentication of choice' the you either use it or not access their site. Are you prepared to not use these monsters of Internet in order to avoid this system? I think it would make for a very 'restricted' view of the WWW