Also if there are probably many people and companies out there working on digital identity projects, simple and real applications could really spark the adoption of such systems, and bloggers are probably a pretty good group of users to start with since they already feel the need for such systems to solve specific problems.

One of the interesting parts of the "You Know Me" Button idea is that comments servers I will post to will not have to store my email address. They won't even have to ever receive my email address since the identity server will guarantee for my identity and, if needed, will be able to forward email messages to me. Of course, this will be applicable to any kind of web application that currently require registrations.

It would also mean that I could block access to my email address to all the services that would not use it properly.

Kung-Log is an application that allows you to post and manage entries of a MovableType weblog. But the interesting thing is its license: it's donation based and the minimal amount of donation is $6.00, but as long as you are a student or someone in between jobs, this app is free for you.