Try out CakePHP
A few months ago I decided to take my php programming to a whole new level and try a framework. There were a few that captured my interest. Symfony, Code Igniter, and CakePHP. I experimented with all 3. I really liked Code Igniter and CakePHP. Code Igniter seems to be very well documented which I felt CakePHP lacked, however, recently CakePHP has come out with The Bakery. This has helped create a more organized way for the community to contribute documentation, tutorials, etc to this framework.
I started getting more comfortable with CakePHP and have decided to make it my framework of choice. It seems to be coming along very well and the development team are extremely active in the usenet groups and IRC channel.
I wrote a very simple authentication component for the project along with a tutorial on how to use it. So if you decide to try out CakePHP for your next project and are looking for simple authentication, try it out.
You can get the component here: http://bakery.cakephp.org/articles/view/130
The tutorial can be viewed here: http://bakery.cakephp.org/articles/view/121