With DockSwap you can change your iPhone/iPod touch dock images from your device itself. Place your doc images in /private/var/root/Library/DockSwap/ and sperated into folders for each category, for example Landscapes, Sports, etc. Images should be interlaced .png files and named anything you like. DockSwap will rename them after you set them. Works fine with SummerBoard.

You can also install customize for DockSwap which will allow you to theme more stuff on your iPhone. Some of the things you can do with customize are change you images for things like home screen background, the carrier image, the WiFi image and more.

Use iPhone mods and hacks at your own risk! Installing 3rd Party iPhone apps requires you to jailbreak the iPhone before installing the native software and apps. You can use Installer.app for Mac OSX and iBrickr for Windows PC to do this. Browse the full list of all iPhone and iPod touch native 3rd party apps filed under the software category.

Get it here