Google is inviting users to "See where your friends are in real time!" by expanding its Maps for Mobile and iGoogle to allow location-sharing, a new functionalty called Google Latitude. Users can decide if they want to share their location information with a select group of friends, and can then be tracked as their pictures are displayed with location information on a map.

Although users can select privacy controls, "the idea of adding one's minute-by-minute whereabouts to Google's vast storehouse of knowledge still has a certain creep factor," TechNewsWorld's Erika Morphy wrote Tuesday.

According to Google, users can share their locations when both parties agree to the sharing. Users can also share, set or hide their locations while using Google Latitude, and can also choose to turn off the service or only share locations by city-level, rather than down to exact address level.

Using Latitude can be done by either downloading Google Maps for mobile with Latitude to their smartphone's mobile browser, or by adding Latitude to their iGoogle homepage.

However, privacy advocates say they are "appalled" by the new function, and children's groups have said government regulators should make sure the system is fully secure, Times Online reported.

"Google is naïve if it thinks there are adequate controls on this feature," Simon Davies, director of Privacy International, told Times Online. He called Latitude a "privacy minefield."