I have always been annoyed by the carrier name taking up a lot of space at the top of my iPhone screen. A few days ago I found a way to insert the much smaller carrier logo without jailbreaking the device.
Just search Google for an IPCC file for your carrier and iOS 5. Download that, go to Terminal and type in the following line:
defaults write com.apple.iTunes carrier-testing -bool TRUE
Connect your iPhone to iTunes and click on "Check for updates" while pressing the Option key. Select the aforementioned IPCC file, and you're done. Unfortunately it seems that the same file cannot be used for an iPad; at least it didn't work for mine.
[kirkmc adds: I didn't test this, and I'd recommend prudence before making this change. There is a chance that this could cause problems with your iPhone. For more about these carrier files, see this Macworld article by Ted Landau, where he explains what they are and what kind of changes you can make to them.
Note that, depending on your carrier, you may already have an IPCC file in ~/Library/iTunes/iPhone Carrier Support.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120329144231807