I tend to stick with jailbreak tweaks that actually have a purpose, but sometimes it’s fun to just mess around. Graviboard is a jailbreak tweak that fits that category perfectly, and the reaction you get when people see it in action never stops being amusing. What it does is to add gravity to your iOS device’s home screen. Icons fall to the end of the screen, slide around when you twist the device, and follow the rules of gravity when you grab them and throw them around.
You can set a few different options, including activation method, so that you can activate the trick by for instance triple clicking home, or shaking the device. It’s available in the Cydia store on jailbroken iOS devices.