NokiaLogo is a free Operator Logo changer for Nokia S60 3rd Edition NSeries and ESeries Mobile Devices such as N73, N80, N95, E60 or E65. Currently you can only set a 128 X 32, black and white picture as a logo. The Operator Logo is a special message stored on your mobile phone under the Mail2 folder. When you run the application for the first time, this utility removes the Mail2 directory and exports the desired logo into it, deleting all the previous messages in it (hence backup is recommended). On an SD Card, this folder is usually located under the \private folder.

Usage Instructions:

1) Create a 128 X 32 Black and white picture
2) Connect the mobile device in the USB mass storage mode
3) Backup the Mail2 folder (only the first time)
4) Run Nokia Logo on your PC
5) Right-click on the default preview image to choose load/reverse/mirror your custom photo (in BMP format), select the correct operator, choose the correct SD Card in the drop down menu and click Export.
6) Disconnect your mobile device and change it into the normal mode
7) Go to Messaging->Options->Settings->Other->Memory in use, use SD card as storage. Then open Inbox and select the message with the logo, and save it

Download NokiaLogo for S60 3rd Edition here

Update: As per a post at Symbian-Freak, to add you own operator to the software, open jarod.opl under SD:\Private\Mail\1000484b\00001001_S\a\0010000a_F with a Hex Editor such as WinHex and edit the first few columns (0 to 3) against offset 00000000 with your own mobile carrier’s MCC/MNC code.