Ryan Petrich has released a new jailbreak utility called "untrackerd," which promises to block iOS from logging your device's location information.
"Petrich's utility comes in the light of a new discovery that Apple's mobile operating system tracks iOS device's longitude and latitude. That location information is then stored on your computer's hard drive and can later be accessed by just about anyone with the right computer skills or software."
Untrackerd is available for free on the Cydia jailbreak store.
Untrackerd's description in Cydia:
Continuously clean up locationd's history data in the background. This package installs a daemon (process that can run in the background) to clean consolidated.db file) No new icons are added to your homescreen. There are no options to configure.