I've searched all through this site, and couldn't find a location for the icon files in iOS 4.2.1. I found the locations, and decided it was so ridiculous I should post something on here for anyone repeating my search. It's bad news friends, all of the icon.png files are located under their individual pathways,
var/mobile/Applications/
and then you'll have to open each individual folder to search for the app you wish to change. An example would be;
0B6F74FD-10B3-43E4-9A30-ED385DE3D71A.
And if you have that one, it's because you have the application "Camera Plus", which you'll see a folder for. After you open that folder you'll have to find the icon.png, and replace it with a new icon.png of your choosing. If you're using an iPhone4, you'll be replacing the icon @ 2x.png, or icon-iPhone @ 2x.png, IF there's one available. It's taken me half an hour to figure this out, and it'll take hours to systematically replace all of my icons... I believe I'll pass on that and keep using a pre-installed theme.
Nevertheless, I decided to share the pathway for anyone else interested. If this is in the wrong thread, please move it. I simply couldn't find a thread for iOS 4.2.1.
I hope this is helpful for someone else!
