This is a discussion thread for the "How to Change Your Carrier Logo Without Jailbreaking" story posted on the front page.
I don't believe it is possible to apply a carrier settings update to these devices, that's the underlying problem. Since these devices lack cellular network connectivity.
He also makes another app that allows some Cydia apps to be downloaded and used on non-jailbroken devices - things like emulators and other apps that wouldn't get past Apple's guidelines. Not tweaks, though.