Zeppelin is a tweak available for a short time in Cydia that allows us to change the carrier logo of our iDevice very simply and easily. The tweak works with iPhone, iPad and iPod Touch and in it we find a predefined list of icons that, as soon as they are selected, replace the carrier logo and the logo for the connection type of our iDevice. Unfortunately, only 11 icons are available in this tweak and none of them are made to display the logo of any mobile operator, so you will have to be content with what you find there.
Zeppelin is a MobileSubstrate tweak to get easy Carrier Logo switching to iOS. It has been tested on iPad, iPhone, and iPod.
Zeppelin is available for free in Cydia in the ModMyi repo and is compatible with iOS 5.