I had an original iPhone 3.1.3 that I jailbroke and added the battery percentage and miwi. It was causing my phone to run really slow, so I restored my phone. But I had left the battery percentage and usb/bluetooth tethering turned on when I restored. Today I noticed with my new iPhone 4 that the battery percentage indicator was turned off in settings, but I still had the percentage showing. I tried turning it off, but I couldn't. So then I checked native tethering and sure enough, there it was. Now I'm waiting to see if ATT can tell before I use it (just like we did when 3.0 was released).