Here is a little tutorial for begginers which will permit you to customize your Status Bar.
For iPhone and iPod Touch, the application Make It Mine is not required.




Required :

• WinterBoard
• A picture .png format with trasnparent background if possible
• Size : 50×20 or 60×20 maxi !Test by yourself !

1) Create a new folder with the name you want like "name.theme"
2) Inside this folder, create 2 folders called Folders and Bundles.

• Folders for iPod Touch.
• Bundles for iPhone.

Folders

Inside this folder, create a folder called SpringBoard.app and paste 2 pictures (the same!) called Default_CARRIER_IPOD.png and FSO_CARRIER_IPOD.png

Bundles

1) Find the name of your carrier in /System/Library/Carrier Bundles
example : com.apple.ATT_US
2) Then, create into the empty folder of Bundles, a folder with the same name as your carrier
Here it is com.apple.ATT_US
3) Paste 2 pictures (the same) in this folder called like your carrier
for the example, it is Default_CARRIER_ATT.png and FSO_CARRIER_ATT.png

Your Theme is finished, you just have to transfer with SSH in /private/var/stash/theme.xxx
and apply in WinterBoard.
If you use Make It Mine, think to tick Carrier option by default !