I think we will always need some way of logging in to websites that deliver personalised content. The login mechanism needs to be able to identify the current user to be able to do this.
There are many ways for this to be achieved eg: username/password, Oauth, some form of secret key.
I don't think we can completely get rid of a login mechanism completely, but it may be possible to hide this from the user.
Face or speech recognition could be used, but I don't really like that idea.
I guess a chip/rfid tag could be implanted into the body, but somehow I don't think most people would want to be identified in this way.
I use http://someonewhocares.org/hosts/ as my hosts file, and it works great. It doesn't remove the placeholder for the ad, but it does stop it from downloading.
[0] - https://github.com/hackedteam