I've been doing research on the location system services specifically the cell network search because 3G drains my battery like no other. People have said that everything works fine with all of these off.
"Cell Network Search is a location based service that sends your location information, and the tower ids of the network towers within range of (and thus detected by) your phone. It is used by Apple marketing (and whomever they choose to sell/share the database with) to determine patterns of cell useage, tower congestion and so on.
Those features in System Services are all about sending your location based information TO Apple, not about enabling features or services on your iPhone. This is Apple's way of allowing you to opt out of the collection of location based data that previously was done surriptiously without overtly letting you know or have any way to stop it.
You can disable every single feature in that section and your iPhone or iPad will continue to function exactly the same way it always has.
The only one that has anything to do with your use is the time zone feature, but you'd only actually need that one on IF you were outside of range of any cellular towers and wanted your time zone set by your GPS location. If you turn it off, but leave the time&date setting on "automatic" then your time zone will be determined by the time signal received from the wireless towers your device connects to."
"I don't have all the links handy, but I found the information on the web at several Mac and cell phone tech news sites. Android and other phones also collect similar location based data and location based data is considered to worth billions of potential revenue for future marketing and targeted features (like traffic based navigation).
Go ahead and disable the compass calibration - your compass will still calibrate just fine. The traffic service sends location based information to Apple, and one rumored use of that data may be a future traffic based navigation service for the iPhone.
These are the optional services that collect location based information from your iPhone and send it to Apple for their use. This information used to be collected secretively, stored on you iPhone and periodically uploaded to Apple's servers. After all the uproar about that in the past, these are now opt-out services.
I disabled all of those settings in Location -> System Services the day I updated to iOS 5, and my iPhone and iPad have continued to work flawlessly, just as they did before. My compass still calibrates when needed, my maps and other traffic apps still get their information, and the cell phone radio still instantly connects to available towers as I move around. Traffic has nothing to do with using traffic based apps or services on your device and disabling it will not affect those apps or services one bit.
Those services have nothing to do with any feature, app, or function on your device. Your phone, nor any cell phone in history, needs a location based database to connect to cell towers. The radio simply detects the towers in range and handshakes with them to establish connection, and hands off to the next nearest tower when you move out of range of the current one.
Google a bit and you'll find lots of technical information about the various uses and proposed uses for location based data being collected by Apple, Google, and other cell phone makers. I'm not necessarily against the practice, and am glad that at least now Apple has at least made it transparent and given users the option to opt-out of these services since that was not possible to do so prior to iOS 5. However, these things must use some battery if on, and will transmit some data, just as the option to automatically send diagnostic&usage data does (although they seem to be programmed to use wifi, not cellular data, and may only dump their data to Apple when syncing as in the past).
As I say, just try it. Disable everything in that Location -> System services section and see if your device behaves in any way, shape or form differently from how it behaved with them on. Those settings have no effect on your device, your apps or how any device features work. They just quietly collect location based information for Apple's use (or potential future use - some of which may be very nice, like a real-time traffic based nav. service)."
