The image above shows an iPhone user's location during travel from New York to Washington.
From the NY Times Bits blog:
"The file, which is called “consolidated.db,” keeps track of GPS data on 3G-enabled Apple devices and regularly updates itself with a user’s location. The image above shows data collected from a single trip between New York City and Washington. Information that is stored on the phone is also sent to the iTunes application when a user syncs or backs up an iPhone or 3G iPad.
In a blog post on the O’Reilly Radar Web site, Mr. Allan said, “The presence of this data on your iPhone, your iPad, and your backups has security and privacy implications.” The two programmers have contacted Apple’s product security team but said they had not yet had a response.
Apple has also not responded to a request for comment from The New York Times."
You can download the iPhone Tracker app here. It will show you the data that has been tracked on your iPhone4 by Apple.
"This open-source application maps the information that your iPhone is recording about your movements. It doesn't record anything itself, it only displays files that are already hidden on your computer."