As has been widely reported today, iPhones have been logging location and timestamps in a file that can easily be accessed on the computer the iPhone is backed up to. This doesn’t seem to pose a massive privacy/security issue since the data never appears to leave the user’s iPhone and the computer it is connected to, but it is understandably getting a lot of attention.
Personally, I’m quite pleased this data exists. I’ve been tracking my location with Google Latitude since it was made available with iOS 4 but this seems to give me a lot more data points. Take a look at my movements in the UK since August last year: