Latitude is a GPS based app from Google that pinpoints your friends' location on a (Google) map. It opens any number of privacy issues, but here's a turn up for the books - it's managed to help apprehend a phone thief.
The crook stole a handbag with a phone that had Latitude installed - the owner says she and her sister had installed it ‘as a joke' to keep tabs on each other - and as soon as he'd snaffled the bag, the sister got on the service, pinpointed his location and called the cops.
The thief was promptly apprehended, the phone returned, and they all lived happily ever after, always knowing where everyone was at all times.
From Tech Digest