Until now, you’ve needed to be selective about what applications are added to the iPhone’s home screen. There are a lot of great 3rd party apps becoming available, but the OS doesn’t have the ability to show more than 16 at a time on the home screen.
Nate True fixed this problem with Dock, an iPhone application that sits on top of the home screen and allows you to scroll through all of your installed applications. Slick.
Dock: iPhone mod to enable scrolling in the home screen – Link