Apple pushes “iPhone Carrier Update” through iTunes sometimes late Friday Night, Feb 06th 2009.
What is it? TUAW talks about it a little bit.
This is what’s inside the “iPhone Carrier Update” for AT&T network (ATT_US.ipcc 32KB)
From carrier.strings
The content corresponds with Carrier Services settings in the iPhone.
Content of carrier.plist
Some un-viewable PNG are also included.