I have recently (tonight) added the ability to login to my blog using OpenID. If you don't know much about OpenID then you might want to have a look at
http://openid.net. If you want to see how I did this then you might want to have a look at my recent blog entry
Why would you want to use OpenID instead of the default username/password? Well perhaps you don't want to send your password to BlogEngine.Net in the clear (assuming you're not using SSL). Or perhaps you are using an OpenID provider that supports Information
Cards so you never have to send your password out into the internet!