You've probably learned recently that your iPhone is tracking your whereabouts. If you don't like this, Untrackerd is a jailbreak app that can put a stop to the problem.
Still haven't jailbroken your iDevice? Check out our guide on jailbreaking for help.
Untrackerd is a quick install through Cydia. It'll put no icon on your home screen and there aren't any settings to configure in your iPhone's Settings app. Untrackerd simply runs in the background and cleans up any location history data that's just sitting on your phone and being sync'd back to your computer. You don't have to do anything other than install it to prevent any future location history from syncing to your machine.
There's no need to install this if you actually like being tracked and having that data accessible to anyone who has access to your computer, but if you'd prefer the additional privacy you can get it very easily by installing Untrackerd.