iPhone iOS 4 Tracking your Location

Well, sort of. It's not identifying you, but it is polling cell towers and keeping a log of them, which keeps a log of where you have been. I'm guessing this is some of the undisclosed anonymous data iTunes asks to send back to Apple, probably to help provide the cell companies data for where they need the most improvements in towers. Just a theory I have. 

You can take a look at where your phone has been tracking you. Check out this article from Tuaw for more info.