Google's Latitude knows where your friends are

Location, location, location

Location, location, location

Google has today launched software called Latitude that lets mobile phone users share their location with close contacts. Google hopes it will help people find each other while out and about and to keep track of loved ones.

Steve Lee, product manager for Google Latitude, said: "What Google Latitude does is allow you to share that location with friends and family members, and likewise be able to see friends and family members' locations."

To protect privacy, Google specifically requires people to sign up for the service. People can share their precise location, the city they're in, or nothing at all.

"What we found in testing is that the most common scenario is a symmetrical arrangement, where both people are sharing with each other," Lee said.

Latitude is part of Google Maps for Mobile, the company's mapping software for mobile phones, but also can be used through a gadget loaded onto its iGoogle customised home page. It'll work in 27 countries at launch, Google said.

Initially, it will work on most colour-screen BlackBerry phones, most phones with Windows Mobile 5.0 or later, and most Symbian-based devices such as Nokia smartphones. An update to the Google Android operating system now being distributed to the T-Mobile G1 phone also enables it, and iPhone and iPod Touch users will get the option "very soon", Lee said.

Latitude uses Google's technology to judge a user's location not just by GPS satellite but also by proximity to mobile phone towers and wireless networks.

That's a much more automated approach than the manual "check-in" process used by Dodgeball, a service Google decided in January to shut down.

Other competitors exist, though: Google's clearest competitor, Yahoo!, offers some competition with Fire Eagle. That service doesn't provide location information, but it does provide a mechanism to centralise people's geographic privacy choices, in effect, taking care of some of the social graph management when it comes to location information.

To use the service, you need a Google account to record who has permission to see your location. For choosing who gets to see your location, you can use contacts stored with Gmail or Picasa, Google said.