If you're jailbroken on iOS 5 you'll definitely want to check out the newly released Springtomize 2. It's by far one of the easiest ways to customize your device running on iOS 5. To start customizing just purchase Springtomize 2 in Cydia then pop into your Settings app and start tweaking every little aspect of your springboard easily and directly from your device.
Springtomize 2 allows you to tweak icons, folders, animations, app switcher, dock, and much more. If you've purchased it already, what are your thoughts? Anything else you'd like to see the ability to customize in a future update?