I am using Code Igniter on two projects at the moment and I am loving it. All the tedious, repetitive elements are reduced, security is increased and code organised in a clean fashion (you can of course mis-use frameworks but with effort they can promote and facilitate a cleaner, more modular approach to coding). In other words I get to work on the meaty part of the application without coding the tedious bits or trapsing through my own past projects to find code I can re-use. It's fast and lightweight and I highlt recommend it - codeigniter.com.