If you’re interested in theming your iPhone/iPod touch, but don’t want to jailbreak your device, there is now a solution. Using iPhone Explorer, you can now change an app’s icon to something you like better. Best of all, the software is free!
All you need to do is open up iPhone Explorer and navigate into the app’s folder, located in /Apps/appname.app/appname.app.app (where appname is the name of the app you want to change and devicename is the name of your device). Within that folder, find the png file that is the icon, named something like icon@2x.png for an
This trick will only work with third party apps, which means that you are stuck with the icons for apps that come with your iPhone.