Settings > Location Services > System Services
What do the 6 items listed in system services actually do, and do the transmit personal information to apple or anyone else.
1. Cell Network Research
2. Compass Calibration (I think this one makes sense)
3. Diagnostics & Usage
4. Location based iAds
5. Setting Time Zone (self explanatory)
6. Traffic (self explanatory)
iPhone 4, iOS 5.1