I was wondering if anybody here who uses PHP frameworks (e.g., CodeIgniter, Cake, Seagull, Zend, etc, etc) could mention which one(s?) they use and why?

For people who actively use more than one, what are the deciding factors regarding what framework you use for what project?

I tend to not use frameworks, but I hear that CakePHP is good. Zend is also quite nice

Symfony is the best! checkouy www.symfony-project.com.
I saw a coupel of projects made by Yahoo! on symfony framework :-)

I've not done much with frameworks but a friend of mine swears by CodeIgniter. I'd suggest trying that one