Implement OpenId authentification. see: http://framework.zend.com/manual/en/zend.openid.consumer.html

Use case: I'm on imdb and a perticular movie seems interresting so I want to know which of my friends saw it. At the moment I have to go to site and search the movie by copy-pasting its title, it's very painfull.

The solution might be to add a little button next to the rating buttons to go directly on the movie page.

When a logged user browse the movie page or the activity page it can be interesting to show his own rating for each movie. For example with a highlighting system:

Our own rating is shown in the title attribute on the movie title, so it is accessible with mouse hover. But graphical highlight is probably much more obvious.

Minimize session usage and instead store data in cookie. But only if non-default value, not to have too big cookies.

Anonymous user should not create session.

Update authentication system for Zend_Auth