Five-Column SpringBoard

Five-Column SpringBoard (FCSB) adds a fifth column to your iPhone home screen. It works on every firmware version on the iPhone from 3.1 to 5.0.

FAQ

Does this work on iOS 5? Yes, nothing has changed with icon lists since iOS 4, so the current version of FCSB works fine on iOS 5.
Why can't I uninstall FCSB? Sadly, some pirate repo has uploaded an ancient version of FCSB that has a broken uninstall script. There is no easy way to uninstall it. But really, what are you doing with a pirate repo installed? :(
What is this error message about something something wildcat? Five-Column SpringBoard only works on iPhones. iPad users can get Iconoclasm on the Cydia Store, which gives you more icon arrangement options, and comes with an FCSB arrangement as its default setting.