If you're worried about your phone tracking your movements and storing that information in a file on your phone, Windows Phone 7 appears to respect your privacy more than does either iOS or Android --- it doesn't store that information in file.
Last week, it was revealed that iPhones and iPads secretly track the locations of their owners, and store that information in an unencrypted file on the owner's mobile device, as well as on the owner's computer.
According to Computerworld, "Stored in the file in clear text are locations' longitude and latitude, a timestamp and other information, including Wi-Fi networks in range of the device."
It's not just iOS that does this; so does Google. On Android phones, "two files called cache.cell and cache.wifi located in the /data/data/com.google.android.location/files directory," reports Read Write Web.
As for Windows Phone 7, PC Magazine says that Microsoft claims they do not store location history.
The big question: Does any of this matter? Yes, it clearly does, for several reasons. First is that when it comes to iOS, there's a possibility that someone can get at the file tracking your location, not on your phone itself, but the one kept on your computer. For those who value their privacy, this can be a frightening thing.
The Android data apparently can't be accessed by other apps on the phone. And as for Windows Phone 7, there are no privacy implications at all, if Microsoft's statement is accurate.
A potentially bigger issue comes down to trust. You're less likely to trust a company whose technology invades your privacy, even if you're not being clearly hurt in any way by it. So in this instance, Apple would be the least trustworthy, and Microsoft the most.